{"id":"CVE-2026-107161","title":"A heap-based buffer overflow flaw was found in Cyrus SASL","summary":"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 …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H","cwe":["CWE-122"],"vendor":"Red Hat","product":"cyrus-sasl","affected":["cyrus-sasl (all versions)","cyrus-sasl","cyrus-sasl (all versions)","cyrus-sasl (all versions)","cyrus-sasl (all versions)","cyrus-sasl (all versions)","openshift/ose-rhel-coreos-8","openshift/ose-rhel-coreos-9"],"published":"2026-10-07","updated":"2026-10-10","sourceUpdated":"2026-10-10T03:17:05.307","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-107161","references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-107161","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2460420","label":"secalert@redhat.com"},{"url":"http://www.openwall.com/lists/oss-security/2026/10/09/20","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-107161.json"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-107161"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-107161"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00337,"epssPercentile":0.26969,"ingestedAt":"2026-10-07T20:46:46.978Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-10T02:42:41.168157Z"},"slug":"CVE-2026-107161","body":"## Overview\n\nA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Hardened Images · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-107161.json)","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}