CVE-2026-107161

Full vulnerability record from the local CVENow database.

Description

A heap-based buffer overflow flaw was found in Cyrus SASL. The add_to_challenge() function in the DIGEST-MD5 plugin computes the size of the buffer needed for a challenge/response field before DIGEST-MD5 quoting is applied, but does not recompute that size when quoting (escaping special characters) makes the value longer. The under-sized buffer is then passed to strcat(), causing a heap-based out-of-bounds write whose size depends on attacker-controlled input. A malicious or on-path DIGEST-MD5 (or HTTP Digest) server can trigger this flaw in a connecting client by supplying a crafted challenge field, such as realm or nonce, most likely resulting in a crash of the client application.

Severity

HIGH

CVSS score

7.5 (v3.1)

Vulnerability status

Awaiting Analysis

Source identifier

[email protected]

Published

2026-10-07 20:17:10.977000

Last modified

2026-10-30 22:16:53.703000

View original CVE JSON

{
  "id": "CVE-2026-107161",
  "sourceIdentifier": "[email protected]",
  "published": "2026-10-07T20:17:10.977",
  "lastModified": "2026-10-30T22:16:53.703",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A heap-based buffer overflow flaw was found in Cyrus SASL. The add_to_challenge() function in the DIGEST-MD5 plugin computes the size of the buffer needed for a challenge/response field before DIGEST-MD5 quoting is applied, but does not recompute that size when quoting (escaping special characters) makes the value longer. The under-sized buffer is then passed to strcat(), causing a heap-based out-of-bounds write whose size depends on attacker-controlled input. A malicious or on-path DIGEST-MD5 (or HTTP Digest) server can trigger this flaw in a connecting client by supplying a crafted challenge field, such as realm or nonce, most likely resulting in a crash of the client application."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 10",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:10"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 6",
          "defaultStatus": "unknown",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:6"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 7",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:7"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 8",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:8"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Enterprise Linux 9",
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          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/o:redhat:enterprise_linux:9"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Hardened Images",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "cyrus-sasl",
          "cpes": [
            "cpe:/a:redhat:hummingbird:1"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Container Platform 4",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "openshift/ose-rhel-coreos-8",
          "cpes": [
            "cpe:/a:redhat:openshift:4"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Container Platform 4",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "openshift/ose-rhel-coreos-9",
          "cpes": [
            "cpe:/a:redhat:openshift:4"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat OpenShift Container Platform 5",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "openshift/ose-rhel-coreos-9",
          "cpes": [
            "cpe:/a:redhat:openshift:5"
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-10T02:42:41.168157Z",
          "id": "CVE-2026-107161",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-107161",
      "source": "[email protected]"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2460420",
      "source": "[email protected]"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/10/09/20",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2026/10/msg00064.html",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}