CVE-2026-54411
Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
Linux-PAM through 1.7.2 contains an observable timing discrepancy (CWE-208) in the pam_userdb module's plaintext-password comparison path in modules/pam_userdb/pam_userdb.c that allows a local or network-adjacent attacker able to repeatedly drive authentication through a calling service to recover the plaintext password of a target account by measuring response-timing differences.
| CWE | CWE-208 |
| Vendor | linux-pam |
| Product | linux-pam |
| Published | Jun 14, 2026 |
| Last Updated | Aug 10, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Affected Versions
Linux-PAM / Linux-PAM
0 ≤ 1.7.2
References
github.com: https://github.com/linux-pam/linux-pam github.com: https://github.com/linux-pam/linux-pam/blob/master/modules/pam_userdb/pam_userdb.c#L327 github.com: https://github.com/linux-pam/linux-pam/blob/master/libpam/include/pam_inline.h cwe.mitre.org: https://cwe.mitre.org/data/definitions/208.html
Credits
Xurshidbek Sobirjonov