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Fencer Intel
medium 5.9

CVE-2026-54411 json

Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison

published 4mo ago modified 3mo ago also EUVD-2026-36662

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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.

Patch / fix

  • pam Ubuntu 22.04 LTS 1.4.0-11ubuntu2.7
  • pam Ubuntu 24.04 LTS 1.5.3-5ubuntu5.6
  • pam Ubuntu 26.04 LTS 1.7.0-5ubuntu3.1

ubuntu advisories UBUNTU-CVE-2026-54411

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • pam RHEL 9 1.5.1-28.el9_8.1
  • pam RHEL 9 1.5.1-27.el9_8.1
  • pam RHEL 10.2 1.6.1-9.el10_2.1
  • pam-libs RHEL 10.2 1.6.1-9.el10_2.1
  • pam RHEL 8 1.3.1-40.el8_10
  • pam hummingbird 1 1.7.2-2.2.hum1
  • pam-libs hummingbird 1 1.7.2-2.2.hum1
  • pam hummingbird 1 1.7.2-1.1.hum1

red hat advisories RHSA-2026:64815RHSA-2026:61230RHSA-2026:61227RHSA-2026:61228RHSA-2026:61229RHSA-2026:61226

  • pam Linux Micro 6.1 1.6.1-slfo.1.1_5.1
  • pam Linux Micro 6.0 1.6.0-6.1
  • pam SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7, SLE Micro 5.5 +2 more 1.3.0-150000.6.89.1
  • pam SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.7.1-160000.5.1
  • pam-full-src SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 1.7.1-160000.5.1
  • pam SLES LTSS Extended Security 12 SP5 1.1.8-24.80.1

suse advisories SUSE-SU-2026:22896-1SUSE-SU-2026:22807-1SUSE-SU-2026:3163-1SUSE-SU-2026:3162-1SUSE-SU-2026:22599-1SUSE-SU-2026:22639-1

  • pam openSUSE Leap 16.0 1.7.1-160000.5.1
  • pam-full-src openSUSE Leap 16.0 1.7.1-160000.5.1
  • pam openSUSE Tumbleweed 1.7.2+git12-2.1

opensuse advisories openSUSE-SU-2026:21320-1openSUSE-SU-2026:11201-1

  • pam AlmaLinux 9 1.5.1-28.el9_8.1
  • pam AlmaLinux 10 1.6.1-9.el10_2.1
  • pam-libs AlmaLinux 10 1.6.1-9.el10_2.1
  • pam AlmaLinux 8 1.3.1-40.el8_10

almalinux advisories ALSA-2026:64815ALSA-2026:59379ALSA-2026:56131

  • pam Rocky Linux 9 1.5.1-28.el9_8.1
  • pam Rocky Linux 10 1.6.1-9.el10_2.1
  • pam Rocky Linux 8 1.3.1-40.el8_10

rocky linux advisories RLSA-2026:64815RLSA-2026:59379RLSA-2026:56131

  • pam Azure Linux 3.0 1.5.3-5

azure linux advisories AZL-90093

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-54411 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-54411 updated cvss 4.8

linux-pam: Plaintext password recovery via timing discrepancy in pam_userdb module

  • Red Hat Enterprise Linux 6 pam
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9 Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat AI Inference Server 3.2 rhaiis/vllm-cuda-rhel9 1790621718, rhaiis/vllm-rocm-rhel9 1790621713, rhaiis/model-opt-cuda-rhel9 1790621714
    fixed: vendor fix RHSA-2026:73859
  • Red Hat AI Inference Server 3.5 rhaii/vllm-cpu-rhel9 1791473614, rhaii/vllm-cuda-rhel9 1791473631, rhaii/vllm-rocm-rhel9 1791425869, rhaii/vllm-gaudi-rhel9 1791427182, rhaii/vllm-spyre-rhel9 1791818357, rhaii/model-opt-cuda-rhel9 1791803821
    fixed: vendor fix RHSA-2026:82066
  • Red Hat Enterprise Linux AI 3.5 rhelai3/bootc-cuda-rhel9 1793135861, rhelai3/bootc-rocm-rhel9 1793135863, rhelai3/bootc-aws-cuda-rhel9 1793194817, rhelai3/bootc-gcp-cuda-rhel9 1793194815, rhelai3/disk-image-cuda-rhel9 1793206758, rhelai3/bootc-azure-cuda-rhel9 1793194815, +1 more
    fixed: vendor fix RHSA-2026:92452
  • Red Hat Enterprise Linux AppStream (v. 9) pam-docs 1.5.1-27.el9_8.1, pam-docs 1.5.1-28.el9_8.1, pam-devel 1.5.1-27.el9_8.1, pam-devel 1.5.1-28.el9_8.1, pam-debuginfo 1.5.1-27.el9_8.1, pam-debuginfo 1.5.1-28.el9_8.1, +2 more
    fixed: vendor fix RHSA-2026:60224
  • Red Hat Enterprise Linux AppStream (v. 10) pam-devel 1.6.1-9.el10_2.1, pam-debuginfo 1.6.1-9.el10_2.1, pam-debugsource 1.6.1-9.el10_2.1, pam-libs-debuginfo 1.6.1-9.el10_2.1
    fixed: vendor fix RHSA-2026:59379
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) pam-docs 1.5.1-15.el9_2.3, pam-devel 1.5.1-15.el9_2.3, pam-debuginfo 1.5.1-15.el9_2.3, pam-debugsource 1.5.1-15.el9_2.3
    fixed: vendor fix RHSA-2026:61226
show 21 more
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) pam-docs 1.5.1-24.el9_4.2, pam-devel 1.5.1-24.el9_4.2, pam-debuginfo 1.5.1-24.el9_4.2, pam-debugsource 1.5.1-24.el9_4.2
    fixed: vendor fix RHSA-2026:61228
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) pam-devel 1.6.1-8.el10_0.1, pam-debuginfo 1.6.1-8.el10_0.1, pam-debugsource 1.6.1-8.el10_0.1, pam-libs-debuginfo 1.6.1-8.el10_0.1
    fixed: vendor fix RHSA-2026:61229
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) pam-docs 1.5.1-26.el9_6.1, pam-devel 1.5.1-26.el9_6.1, pam-debuginfo 1.5.1-26.el9_6.1, pam-debugsource 1.5.1-26.el9_6.1
    fixed: vendor fix RHSA-2026:61230
  • Red Hat Enterprise Linux BaseOS (v. 8) pam 1.3.1-40.el8_10
    fixed: vendor fix RHSA-2026:56131
  • Red Hat Enterprise Linux BaseOS (v. 9) pam 1.5.1-27.el9_8.1, pam 1.5.1-28.el9_8.1
    fixed: vendor fix RHSA-2026:60224
  • Red Hat Enterprise Linux BaseOS (v. 10) pam 1.6.1-9.el10_2.1, pam-libs 1.6.1-9.el10_2.1
    fixed: vendor fix RHSA-2026:59379
  • Red Hat Enterprise Linux BaseOS AUS (v.8.4) pam 1.3.1-14.el8_4.3
    fixed: vendor fix RHSA-2026:61224
  • Red Hat Enterprise Linux BaseOS AUS (v.8.6) pam 1.3.1-16.el8_6.4
    fixed: vendor fix RHSA-2026:61223
  • Red Hat Enterprise Linux BaseOS E4S (v.8.8) pam 1.3.1-26.el8_8.3
    fixed: vendor fix RHSA-2026:61225
  • Red Hat Enterprise Linux BaseOS E4S (v.9.2) pam 1.5.1-15.el9_2.3
    fixed: vendor fix RHSA-2026:61226
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) pam 1.5.1-24.el9_4.2
    fixed: vendor fix RHSA-2026:61228
  • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) pam 1.6.1-8.el10_0.1, pam-libs 1.6.1-8.el10_0.1
    fixed: vendor fix RHSA-2026:61229
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) pam 1.5.1-26.el9_6.1
    fixed: vendor fix RHSA-2026:61230
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) pam 1.3.1-14.el8_4.3
    fixed: vendor fix RHSA-2026:61224
  • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) pam 1.3.1-16.el8_6.4
    fixed: vendor fix RHSA-2026:61223
  • Red Hat Enterprise Linux BaseOS TUS (v.8.8) pam 1.3.1-26.el8_8.3
    fixed: vendor fix RHSA-2026:61225
  • Red Hat Enterprise Linux Server (v. 7 ELS) pam 1.1.8-23.el7_9.3
    fixed: vendor fix RHSA-2026:61227
  • Red Hat Hardened Images pam 1.7.2-1.1.hum1, pam 1.7.2-2.2.hum1, pam-libs 1.7.2-1.1.hum1, pam-libs 1.7.2-2.2.hum1
    fixed: vendor fix RHSA-2026:7553
  • Red Hat OpenShift AI 3.0 rhai/base-image-cpu-rhel9 1790277045, rhai/base-image-tpu-rhel9 1790276884, rhai/base-image-cuda-rhel9 1790276974, rhai/base-image-rocm-rhel9 1790276886, rhai/base-image-spyre-rhel9 1790276889
    fixed: vendor fix RHSA-2026:73960
  • Red Hat OpenShift AI 3.2 rhai/base-image-cpu-rhel9 1790703590, rhai/base-image-tpu-rhel9 1790703497, rhai/base-image-cuda-rhel9 1790703586, rhai/base-image-rocm-rhel9 1790703494, rhai/base-image-rocm-rhel9 1790703506, rhai/base-image-spyre-rhel9 1790703568
    fixed: vendor fix RHSA-2026:74460
  • Red Hat OpenShift AI 3.4 rhai/base-image-neuron-rhel9 1790703542
    fixed: vendor fix RHSA-2026:74674

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 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
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 4.0 6.9 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

Affected products

  • Linux-PAM Linux-PAM

Classification

Weakness
  • CWE-208 Observable Timing Discrepancy

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.