CVE-2026-54411
Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison
02 Description
Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.32% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 24.8% of scored records. A rank, not a probability.
- NVD base score
- 6.9 (CVSS v4.0), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:N/R:X/V:D/RE:X/U:X
- NVD analysis status
- Deferred. NVD last modified this record on 2026-08-10.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-06-14 17:21Z4 MO AGO
- Last updated
- 2026-08-10 11:43Z2 MO AGO
- Reserved
- 2026-06-13
- Assigning CNA
- TuranSec
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 6.9)
- CNA CVSS vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/AU:N/V:D
- Weaknesses
- CWE-208Observable Timing DiscrepancyBase
- Data version
- 5.2
- Document digest
- ef6d523acdb6b090c1d16d379221f3d716b611266b81d4d3f95e52e58f0736b3
05 Affected products
06 References
- github.comLinux-PAM - upstream repositoryhttps://github.com/linux-pam/linux-pam
- github.comVulnerable plaintext-password comparison in pam_userdb.c (master)https://github.com/linux-pam/linux-pam/blob/master/modules/pam_userdb/pam_userdb.c#L327
- github.compam_consttime_streq helper available for the remediationhttps://github.com/linux-pam/linux-pam/blob/master/libpam/include/pam_inline.h
- cwe.mitre.orgCWE-208: Observable Timing Discrepancyhttps://cwe.mitre.org/data/definitions/208.html
07 Fixed in
AlmaLinux 8
- pam Fixed in 1.3.1-40.el8_10
- pam-devel Fixed in 1.3.1-40.el8_10
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- pam Fixed in 1.5.1-28.el9_8.1
- pam-devel Fixed in 1.5.1-28.el9_8.1
- pam-docs Fixed in 1.5.1-28.el9_8.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- pam Fixed in 1.6.1-9.el10_2.1
- pam-devel Fixed in 1.6.1-9.el10_2.1
- pam-libs Fixed in 1.6.1-9.el10_2.1
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- pam Fixed in 1.3.1-40.el8_10
- pam-devel Fixed in 1.3.1-40.el8_10
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- pam Fixed in 1.5.1-28.el9_8.1
- pam-devel Fixed in 1.5.1-28.el9_8.1
- pam-docs Fixed in 1.5.1-28.el9_8.1
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 10
- pam Fixed in 1.6.1-9.el10_2.1
- pam-devel Fixed in 1.6.1-9.el10_2.1
- pam-libs Fixed in 1.6.1-9.el10_2.1
Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- pam No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- pam No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- pam No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- pam Fixed in 1.4.0-11ubuntu2.7
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- pam Fixed in 1.5.3-5ubuntu5.6
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 25.10
- pam No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- pam Fixed in 1.7.0-5ubuntu3.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- pam No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- pam No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- pam No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- pam No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.