GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration
ubuntu-cve-2026-31790
Vulnerability from osv_ubuntu
Published
2026-04-07 00:00
Modified
2026-09-15 06:14
Summary
Details

Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.23"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.23"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.23?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.2-0ubuntu1.23"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.1l-1ubuntu1",
        "3.0.0-1ubuntu1",
        "3.0.1-0ubuntu1",
        "3.0.2-0ubuntu1",
        "3.0.2-0ubuntu1.1",
        "3.0.2-0ubuntu1.2",
        "3.0.2-0ubuntu1.4",
        "3.0.2-0ubuntu1.5",
        "3.0.2-0ubuntu1.6",
        "3.0.2-0ubuntu1.7",
        "3.0.2-0ubuntu1.8",
        "3.0.2-0ubuntu1.9",
        "3.0.2-0ubuntu1.10",
        "3.0.2-0ubuntu1.12",
        "3.0.2-0ubuntu1.13",
        "3.0.2-0ubuntu1.14",
        "3.0.2-0ubuntu1.15",
        "3.0.2-0ubuntu1.16",
        "3.0.2-0ubuntu1.17",
        "3.0.2-0ubuntu1.18",
        "3.0.2-0ubuntu1.19",
        "3.0.2-0ubuntu1.20",
        "3.0.2-0ubuntu1.21"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.12+Fips1"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.12+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-preview:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.12+Fips1?arch=source\u0026distro=fips-preview/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.2-0ubuntu1.10+Fips1",
        "3.0.2-0ubuntu1.12+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.5-0ubuntu0.1+Fips2.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-preview:22.04:LTS",
        "name": "openssl-fips",
        "purl": "pkg:deb/ubuntu/openssl-fips@3.0.5-0ubuntu0.1+Fips2.1?arch=source\u0026distro=fips-preview/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.5-0ubuntu0.1+Fips2.1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libssl3",
            "binary_version": "3.0.2-0ubuntu1.29+Fips1"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.29+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.29+Fips1?arch=source\u0026distro=fips-updates/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.2-0ubuntu1.10+Fips1",
        "3.0.2-0ubuntu1.12+Fips1",
        "3.0.2-0ubuntu1.14+Fips1",
        "3.0.2-0ubuntu1.15+Fips1",
        "3.0.2-0ubuntu1.16+Fips1",
        "3.0.2-0ubuntu1.17+Fips1",
        "3.0.2-0ubuntu1.18+Fips1",
        "3.0.2-0ubuntu1.19+Fips1",
        "3.0.2-0ubuntu1.20+Fips1",
        "3.0.2-0ubuntu1.21+Fips1",
        "3.0.2-0ubuntu1.23+Fips1",
        "3.0.2-0ubuntu1.25+Fips1",
        "3.0.2-0ubuntu1.26+Fips1",
        "3.0.2-0ubuntu1.29+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.5-0ubuntu0.2+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:22.04:LTS",
        "name": "openssl-fips",
        "purl": "pkg:deb/ubuntu/openssl-fips@3.0.5-0ubuntu0.2+Fips1?arch=source\u0026distro=fips-updates/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.5-0ubuntu0.1+Fips2.1",
        "3.0.5-0ubuntu0.2+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "efi-shell-aa64",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "efi-shell-arm",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "efi-shell-ia32",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "efi-shell-x64",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "ovmf",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "ovmf-ia32",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "ovmf-legacy",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "qemu-efi-arm",
            "binary_version": "2024.02-2ubuntu0.9"
          },
          {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2024.02-2ubuntu0.9"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "edk2",
        "purl": "pkg:deb/ubuntu/edk2@2024.02-2ubuntu0.9?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2023.05-2",
        "2023.11-2",
        "2023.11-3",
        "2023.11-4",
        "2023.11-5",
        "2023.11-6",
        "2023.11-8",
        "2024.02-1",
        "2024.02-2",
        "2024.02-2ubuntu0.1",
        "2024.02-2ubuntu0.3",
        "2024.02-2ubuntu0.4",
        "2024.02-2ubuntu0.5",
        "2024.02-2ubuntu0.6",
        "2024.02-2ubuntu0.7",
        "2024.02-2ubuntu0.8",
        "2024.02-2ubuntu0.9"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3t64",
            "binary_version": "3.0.13-0ubuntu3.9"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.13-0ubuntu3.9"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.13-0ubuntu3.9?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.13-0ubuntu3.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.10-1ubuntu2",
        "3.0.10-1ubuntu2.1",
        "3.0.10-1ubuntu3",
        "3.0.10-1ubuntu4",
        "3.0.13-0ubuntu2",
        "3.0.13-0ubuntu3",
        "3.0.13-0ubuntu3.1",
        "3.0.13-0ubuntu3.2",
        "3.0.13-0ubuntu3.3",
        "3.0.13-0ubuntu3.4",
        "3.0.13-0ubuntu3.5",
        "3.0.13-0ubuntu3.6",
        "3.0.13-0ubuntu3.7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.13-0ubuntu3.12+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:24.04:LTS",
        "name": "openssl-fips",
        "purl": "pkg:deb/ubuntu/openssl-fips@3.0.13-0ubuntu3.12+Fips1?arch=source\u0026distro=fips-updates/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.13-0ubuntu3.12+Fips1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.13-0ubuntu3+Fips1",
        "3.0.13-0ubuntu3.6+Fips1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "efi-shell-aa64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "efi-shell-arm",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "efi-shell-ia32",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "efi-shell-loongarch64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "efi-shell-x64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "ovmf",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "ovmf-ia32",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "ovmf-inteltdx",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "ovmf-legacy",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "qemu-efi-arm",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "qemu-efi-loongarch64",
            "binary_version": "2025.02-8ubuntu3.2"
          },
          {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2025.02-8ubuntu3.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "edk2",
        "purl": "pkg:deb/ubuntu/edk2@2025.02-8ubuntu3.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2025.02-3ubuntu2",
        "2025.02-8",
        "2025.02-8ubuntu1",
        "2025.02-8ubuntu2",
        "2025.02-8ubuntu3",
        "2025.02-8ubuntu3.1",
        "2025.02-8ubuntu3.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3t64",
            "binary_version": "3.5.3-1ubuntu3.3"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.5.3-1ubuntu3.3"
          },
          {
            "binary_name": "openssl-provider-legacy",
            "binary_version": "3.5.3-1ubuntu3.3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.5.3-1ubuntu3.3?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.5.3-1ubuntu3.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.4.1-1ubuntu3",
        "3.5.0-2ubuntu1",
        "3.5.2-1ubuntu1",
        "3.5.3-1ubuntu2",
        "3.5.3-1ubuntu3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "efi-shell-aa64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "efi-shell-loongarch64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "efi-shell-x64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "ovmf",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "ovmf-amdsev",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "ovmf-generic",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "ovmf-inteltdx",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "ovmf-legacy",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "qemu-efi-loongarch64",
            "binary_version": "2025.11-3ubuntu7.2"
          },
          {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2025.11-3ubuntu7.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "edk2",
        "purl": "pkg:deb/ubuntu/edk2@2025.11-3ubuntu7.2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2025.02-8ubuntu3",
        "2025.11-3ubuntu6",
        "2025.11-3ubuntu7",
        "2025.11-3ubuntu7.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "efi-shell-aa64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "efi-shell-loongarch64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "efi-shell-riscv64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "efi-shell-x64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "ovmf-amdsev-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "ovmf-generic-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "ovmf-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "ovmf-inteltdx-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "ovmf-legacy-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "qemu-efi-aarch64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "qemu-efi-loongarch64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          },
          {
            "binary_name": "qemu-efi-riscv64-hwe",
            "binary_version": "2025.11-3ubuntu8.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "edk2-hwe",
        "purl": "pkg:deb/ubuntu/edk2-hwe@2025.11-3ubuntu8.2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2025.11-3ubuntu6",
        "2025.11-3ubuntu8",
        "2025.11-3ubuntu8.2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "libssl3t64",
            "binary_version": "3.5.5-1ubuntu3"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.5.5-1ubuntu3"
          },
          {
            "binary_name": "openssl-provider-legacy",
            "binary_version": "3.5.5-1ubuntu3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.5.5-1ubuntu3?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.5.5-1ubuntu3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.5.3-1ubuntu2",
        "3.5.5-1ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.",
  "id": "UBUNTU-CVE-2026-31790",
  "modified": "2026-09-15T06:14:18Z",
  "published": "2026-04-07T00:00:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-31790"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-31790"
    },
    {
      "type": "REPORT",
      "url": "https://www.openwall.com/lists/oss-security/2026/04/07/11"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8155-1"
    }
  ],
  "related": [
    "USN-8155-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-31790"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.