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High ALAS2-2026-4029 1 CVE

Important: cyrus-sasl security update (Amazon Linux 2)

Published Oct 26, 2026 · Updated Oct 26, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: 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.

Fixed packages 12

ReleasePackageFixed in
Amazon Linux · 2 cyrus-sasl 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-debuginfo 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-devel 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-gs2 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-gssapi 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-ldap 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-lib 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-md5 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-ntlm 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-plain 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-scram 0:2.1.26-24.amzn2.0.2
Amazon Linux · 2 cyrus-sasl-sql 0:2.1.26-24.amzn2.0.2

Vulnerabilities 1

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-107161.html