CVE-2026-107161
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk19th percentile - higher than 19% of all known CVEs
Summary
Heap-based buffer overflow in Cyrus SASL. The add_to_challenge() function in the DIGEST-MD5 plugin does not recompute buffer size after quoting, leading to out-of-bounds write. A malicious server can crash the client.
Risk Assessment
The risk is that a remote server can crash client applications, potentially disrupting services.
Recommendation
Upgrade Cyrus SASL to a patched version and limit trust in DIGEST-MD5 servers.
Other vulnerabilities in Cyrus SASL
See all- CVE-2019-19906High
cyrus-sasl 2.1.27 has an out-of-bounds write leading to unauthenticated remote denial-of-service in OpenLDAP via a malformed LDAP packet. The OpenLDAP crash is caused by an off-by-one error in _sasl_add_string in common.c.
- CVE-2000-0956Medium
cyrus-sasl before version 1.5.24 in Red Hat Linux 7.0 does not properly verify the authorization for a local user, which could allow users to bypass specified access restrictions.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS