Out-of-bounds Read in Fedoraproject Sssd

CVE-2026-68743

A flaw was found in SSSD. The extract_authtok_v1() function in the PAM responder does not validate the auth_token_length field against the remaining buffer size before processing. A local attacker can exploit this via a crafted protocol v1 request to the PAM responder socket, causing an out-of-bounds read and process crash, resulting in a denial of service.

Vulnerability class: Buffer Overflow

EPSS: 0.001 (0.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-68743?
CVE-2026-68743 is a medium-severity vulnerability in Fedoraproject Sssd, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-08-04.
How severe is CVE-2026-68743?
Medium severity. CVSS v3 base score is 5.5 out of 10.