GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-22693 (GCVE-0-2026-22693)

Vulnerability from cvelistv5 – Published: 2026-01-10 05:53 – Updated: 2026-01-12 16:47
VLAI
Title
Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS
Summary
HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-01-12 16:46 UTC
CWE
  • CWE-476 - NULL Pointer Dereference
Assigner
References
Impacted products
Vendor Product Version CPE status
harfbuzz harfbuzz Affected: < 12.3.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-01-12T05:10:58.184Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/01/11/1"
          },
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/01/12/1"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-22693",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-12T16:46:05.339668Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-01-12T16:47:17.715Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "harfbuzz",
          "vendor": "harfbuzz",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 12.3.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476: NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-10T05:53:21.019Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/harfbuzz/harfbuzz/security/advisories/GHSA-xvjr-f2r9-c7ww",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/harfbuzz/harfbuzz/security/advisories/GHSA-xvjr-f2r9-c7ww"
        },
        {
          "name": "https://github.com/harfbuzz/harfbuzz/commit/1265ff8d990284f04d8768f35b0e20ae5f60daae",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/harfbuzz/harfbuzz/commit/1265ff8d990284f04d8768f35b0e20ae5f60daae"
        }
      ],
      "source": {
        "advisory": "GHSA-xvjr-f2r9-c7ww",
        "discovery": "UNKNOWN"
      },
      "title": "Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-22693",
    "datePublished": "2026-01-10T05:53:21.019Z",
    "dateReserved": "2026-01-08T19:23:09.855Z",
    "dateUpdated": "2026-01-12T16:47:17.715Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-22693",
      "date": "2026-09-20",
      "epss": "0.00442",
      "percentile": "0.37798"
    },
    "microsoft_vex": {
      "current_release_date": "2026-01-20T14:47:26.000Z",
      "cve": "CVE-2026-22693",
      "id": "msrc_CVE-2026-22693",
      "initial_release_date": "2026-01-02T00:00:00.000Z",
      "product_status:fixed": "2",
      "product_status:known_affected": "2",
      "product_status:known_not_affected": "3",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-22693.json",
      "version": "5"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "harfbuzz",
                "vendor": "harfbuzz",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 12.3.0"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:harfbuzz_project:harfbuzz:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "394555F9-FE83-460B-B30E-11AFE2B9C748",
                    "versionEndExcluding": "12.3.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0."
          },
          {
            "lang": "es",
            "value": "HarfBuzz es un motor de conformaci\u00f3n de texto. Antes de la versi\u00f3n 12.3.0, existe una vulnerabilidad de desreferencia de puntero nulo en la funci\u00f3n SubtableUnicodesCache::create ubicada en src/hb-ot-cmap-table.hh. La funci\u00f3n no verifica si hb_malloc devuelve NULL antes de usar \u0027placement new\u0027 para construir un objeto en la direcci\u00f3n de puntero devuelta. Cuando hb_malloc falla al asignar memoria (lo que puede ocurrir en condiciones de poca memoria o al usar asignadores personalizados que simulan fallos de asignaci\u00f3n), devuelve NULL. El c\u00f3digo entonces intenta llamar al constructor en este puntero nulo usando la sintaxis de \u0027placement new\u0027, lo que resulta en un comportamiento indefinido y un Fallo de Segmentaci\u00f3n. Este problema ha sido parcheado en la versi\u00f3n 12.3.0."
          }
        ],
        "id": "CVE-2026-22693",
        "lastModified": "2026-06-17T10:20:14.783",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 1.4,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2026-22693",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "yes"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-01-12T16:46:05.339668Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2026-01-10T06:15:52.063",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch"
            ],
            "url": "https://github.com/harfbuzz/harfbuzz/commit/1265ff8d990284f04d8768f35b0e20ae5f60daae"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Exploit",
              "Mitigation",
              "Vendor Advisory"
            ],
            "url": "https://github.com/harfbuzz/harfbuzz/security/advisories/GHSA-xvjr-f2r9-c7ww"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Mailing List",
              "Patch",
              "Third Party Advisory"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2026/01/11/1"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Mailing List",
              "Patch",
              "Third Party Advisory"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2026/01/12/1"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Analyzed",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-476"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-07-02T17:11:49+00:00",
      "cve": "CVE-2026-22693",
      "id": "CVE-2026-22693",
      "initial_release_date": "2026-01-10T05:53:21.019000+00:00",
      "product_status:fixed": "3",
      "product_status:known_affected": "214",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "harfbuzz: Null Pointer Dereference in harfbuzz",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-22693.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-11T01:38:35Z",
      "cve": "CVE-2026-22693",
      "id": "CVE-2026-22693",
      "initial_release_date": "2026-01-13T00:24:09Z",
      "product_status:known_affected": "447",
      "product_status:known_not_affected": "237",
      "product_status:recommended": "94",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-22693",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-22693.json",
      "version": "16"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2026-01-12T05:10:58.184Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/01/11/1"
              },
              {
                "url": "http://www.openwall.com/lists/oss-security/2026/01/12/1"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2026-22693",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "yes"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2026-01-12T16:46:05.339668Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2026-01-12T16:46:41.390Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "product": "harfbuzz",
              "vendor": "harfbuzz",
              "versions": [
                {
                  "status": "affected",
                  "version": "\u003c 12.3.0"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "HarfBuzz is a text shaping engine. Prior to version 12.3.0, a null pointer dereference vulnerability exists in the SubtableUnicodesCache::create function located in src/hb-ot-cmap-table.hh. The function fails to check if hb_malloc returns NULL before using placement new to construct an object at the returned pointer address. When hb_malloc fails to allocate memory (which can occur in low-memory conditions or when using custom allocators that simulate allocation failures), it returns NULL. The code then attempts to call the constructor on this null pointer using placement new syntax, resulting in undefined behavior and a Segmentation Fault. This issue has been patched in version 12.3.0."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "LOW",
                "baseScore": 5.3,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
                "version": "3.1"
              }
            }
          ],
          "problemTypes": [
            {
              "descriptions": [
                {
                  "cweId": "CWE-476",
                  "description": "CWE-476: NULL Pointer Dereference",
                  "lang": "en",
                  "type": "CWE"
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-01-10T05:53:21.019Z",
            "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
            "shortName": "GitHub_M"
          },
          "references": [
            {
              "name": "https://github.com/harfbuzz/harfbuzz/security/advisories/GHSA-xvjr-f2r9-c7ww",
              "tags": [
                "x_refsource_CONFIRM"
              ],
              "url": "https://github.com/harfbuzz/harfbuzz/security/advisories/GHSA-xvjr-f2r9-c7ww"
            },
            {
              "name": "https://github.com/harfbuzz/harfbuzz/commit/1265ff8d990284f04d8768f35b0e20ae5f60daae",
              "tags": [
                "x_refsource_MISC"
              ],
              "url": "https://github.com/harfbuzz/harfbuzz/commit/1265ff8d990284f04d8768f35b0e20ae5f60daae"
            }
          ],
          "source": {
            "advisory": "GHSA-xvjr-f2r9-c7ww",
            "discovery": "UNKNOWN"
          },
          "title": "Null Pointer Dereference in SubtableUnicodesCache::create leading to DoS"
        }
      },
      "cveMetadata": {
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "assignerShortName": "GitHub_M",
        "cveId": "CVE-2026-22693",
        "datePublished": "2026-01-10T05:53:21.019Z",
        "dateReserved": "2026-01-08T19:23:09.855Z",
        "dateUpdated": "2026-01-12T16:47:17.715Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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.