CVE-2026-107161

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.6 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/security/cve/CVE-2026-107161
https://bugzilla.redhat.com/show_bug.cgi?id=2460420
http://www.openwall.com/lists/oss-security/2026/10/09/20
https://lists.debian.org/debian-lts-announce/2026/10/msg00064.html

Configurations

No configuration.

History

30 Oct 2026, 21:16

Type	Values Removed	Values Added
References		() https://lists.debian.org/debian-lts-announce/2026/10/msg00064.html -

09 Oct 2026, 23:16

Type	Values Removed	Values Added
References		() http://www.openwall.com/lists/oss-security/2026/10/09/20 -

07 Oct 2026, 20:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-07 20:17

Updated : 2026-10-30 22:16

NVD link : CVE-2026-107161

Mitre link : CVE-2026-107161

CVE.ORG link : CVE-2026-107161

JSON object : View

Products Affected

No product.

CWE

CWE-122

Heap-based Buffer Overflow

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