CVE-2026-107161
HIGH
MEDIUM
Priority: 0.03
BB Relevance:
55/100
Published: 2026-10-07
Modified: 2026-10-30
First seen: 2026-10-30
Status: active
Attack Surface
Network
No Auth
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
Required
S:
Unchanged
C:
High
I:
High
A:
High
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.