ubuntu-cve-2026-31790
Vulnerability from osv_ubuntu
Published
2026-04-07 00:00
Modified
2026-07-08 20:55
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": "3.0.2-0ubuntu1.25+Fips1"
          },
          {
            "binary_name": "openssl",
            "binary_version": "3.0.2-0ubuntu1.25+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:22.04:LTS",
        "name": "openssl",
        "purl": "pkg:deb/ubuntu/openssl@3.0.2-0ubuntu1.25+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"
      ]
    },
    {
      "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": {
        "binaries": [
          {
            "binary_name": "openssl-fips-module-3",
            "binary_version": "3.0.13-0ubuntu3.6+Fips1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:FIPS-updates:24.04:LTS",
        "name": "openssl-fips",
        "purl": "pkg:deb/ubuntu/openssl-fips@3.0.13-0ubuntu3.6+Fips1?arch=source\u0026distro=fips-updates/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "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"
          },
          {
            "binary_name": "efi-shell-loongarch64",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "efi-shell-riscv64",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "efi-shell-x64",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "ovmf",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "ovmf-amdsev",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "ovmf-generic",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "ovmf-inteltdx",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "ovmf-legacy",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "qemu-efi-aarch64",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "qemu-efi-loongarch64",
            "binary_version": "2025.11-3ubuntu7"
          },
          {
            "binary_name": "qemu-efi-riscv64",
            "binary_version": "2025.11-3ubuntu7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "edk2",
        "purl": "pkg:deb/ubuntu/edk2@2025.11-3ubuntu7?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2025.02-8ubuntu3",
        "2025.11-3ubuntu6",
        "2025.11-3ubuntu7"
      ]
    },
    {
      "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": "2026-07-08T20:55:15Z",
  "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.