FKIE_CVE-2026-22796

Vulnerability from fkie_nvd - Published: 2026-01-27 16:16 - Updated: 2026-02-02 18:40
Severity ?
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
Issue summary: A type confusion vulnerability exists in the signature verification of signed PKCS#7 data where an ASN1_TYPE union member is accessed without first validating the type, causing an invalid or NULL pointer dereference when processing malformed PKCS#7 data. Impact summary: An application performing signature verification of PKCS#7 data or calling directly the PKCS7_digest_from_attributes() function can be caused to dereference an invalid or NULL pointer when reading, resulting in a Denial of Service. The function PKCS7_digest_from_attributes() accesses the message digest attribute value without validating its type. When the type is not V_ASN1_OCTET_STRING, this results in accessing invalid memory through the ASN1_TYPE union, causing a crash. Exploiting this vulnerability requires an attacker to provide a malformed signed PKCS#7 to an application that verifies it. The impact of the exploit is just a Denial of Service, the PKCS7 API is legacy and applications should be using the CMS API instead. For these reasons the issue was assessed as Low severity. The FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the PKCS#7 parsing implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue.
References
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/2502e7b7d4c0cf4f972a881641fe09edc67aeec4Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/572844beca95068394c916626a6d3a490f831a49Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/7bbca05be55b129651d9df4bdb92becc45002c12Patch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/eeee3cbd4d682095ed431052f00403004596373ePatch
openssl-security@openssl.orghttps://github.com/openssl/openssl/commit/ef2fb66ec571564d64d1c74a12e388a2a54d05d2Patch
openssl-security@openssl.orghttps://openssl-library.org/news/secadv/20260127.txtVendor Advisory
Impacted products
Vendor Product Version
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
openssl openssl *
To clipboard 

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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Issue summary: A type confusion vulnerability exists in the signature\nverification of signed PKCS#7 data where an ASN1_TYPE union member is\naccessed without first validating the type, causing an invalid or NULL\npointer dereference when processing malformed PKCS#7 data.\n\nImpact summary: An application performing signature verification of PKCS#7\ndata or calling directly the PKCS7_digest_from_attributes() function can be\ncaused to dereference an invalid or NULL pointer when reading, resulting in\na Denial of Service.\n\nThe function PKCS7_digest_from_attributes() accesses the message digest attribute\nvalue without validating its type. When the type is not V_ASN1_OCTET_STRING,\nthis results in accessing invalid memory through the ASN1_TYPE union, causing\na crash.\n\nExploiting this vulnerability requires an attacker to provide a malformed\nsigned PKCS#7 to an application that verifies it. The impact of the\nexploit is just a Denial of Service, the PKCS7 API is legacy and applications\nshould be using the CMS API instead. For these reasons the issue was\nassessed as Low severity.\n\nThe FIPS modules in 3.5, 3.4, 3.3 and 3.0 are not affected by this issue,\nas the PKCS#7 parsing implementation is outside the OpenSSL FIPS module\nboundary.\n\nOpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are vulnerable to this issue."
    },
    {
      "lang": "es",
      "value": "Resumen del problema: Existe una vulnerabilidad de confusi\u00f3n de tipos en la verificaci\u00f3n de firma de datos PKCS#7 firmados, donde se accede a un miembro de la uni\u00f3n ASN1_TYPE sin validar primero el tipo, causando una desreferencia de puntero inv\u00e1lido o NULL al procesar datos PKCS#7 malformados.\n\nResumen del impacto: Una aplicaci\u00f3n que realiza la verificaci\u00f3n de firma de datos PKCS#7 o que llama directamente a la funci\u00f3n PKCS7_digest_from_attributes() puede ser inducida a desreferenciar un puntero inv\u00e1lido o NULL al leer, resultando en una denegaci\u00f3n de servicio.\n\nLa funci\u00f3n PKCS7_digest_from_attributes() accede al valor del atributo de resumen del mensaje sin validar su tipo. Cuando el tipo no es V_ASN1_OCTET_STRING, esto resulta en el acceso a memoria inv\u00e1lida a trav\u00e9s de la uni\u00f3n ASN1_TYPE, causando un fallo.\n\nExplotar esta vulnerabilidad requiere que un atacante proporcione un PKCS#7 firmado malformado a una aplicaci\u00f3n que lo verifica. El impacto del exploit es solo una denegaci\u00f3n de servicio, la API PKCS7 es heredada y las aplicaciones deber\u00edan usar la API CMS en su lugar. Por estas razones, el problema fue evaluado como de baja severidad.\n\nLos m\u00f3dulos FIPS en 3.5, 3.4, 3.3 y 3.0 no se ven afectados por este problema, ya que la implementaci\u00f3n de an\u00e1lisis de PKCS#7 est\u00e1 fuera del l\u00edmite del m\u00f3dulo FIPS de OpenSSL.\n\nOpenSSL 3.6, 3.5, 3.4, 3.3, 3.0, 1.1.1 y 1.0.2 son vulnerables a este problema."
    }
  ],
  "id": "CVE-2026-22796",
  "lastModified": "2026-02-02T18:40:27.467",
  "metrics": {
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          "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"
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        "impactScore": 1.4,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
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  "published": "2026-01-27T16:16:35.543",
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  "sourceIdentifier": "openssl-security@openssl.org",
  "vulnStatus": "Analyzed",
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          "value": "CWE-754"
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      "source": "openssl-security@openssl.org",
      "type": "Secondary"
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}


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  • 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.
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  • 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.