CVE-2026-54411 Linux-PAM pam_userdb Observable Timing Discrepancy in Plaintext Password Comparison
Medium 6.9
Published
Updated
Check this codebase for CVE-2026-54411 and fix it if it is affected.
What it is: CVE-2026-54411 is a medium-severity vulnerability in Linux-PAM, published on 14 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-54411 in the wild and no public exploit code.
Affected product: Linux-PAM. No package-level version data is available, so check the vendor advisory linked from the reference page.
Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.
Reference: https://insights.sbomify.com/CVE-2026-54411/ (Markdown: https://insights.sbomify.com/CVE-2026-54411/index.md)
An attacker can recover plaintext passwords by measuring timing differences during authentication in the Linux-PAM pam_userdb module.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54411?
CVE-2026-54411 is a medium-severity vulnerability in Linux-PAM, published on 14 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-208
Which versions are affected by CVE-2026-54411?
Linux distribution packages (40)
pam AlmaLinux:10 | All versions | 1.6.1-9.el10_2.1 |
pam-devel AlmaLinux:10 | All versions | 1.6.1-9.el10_2.1 |
pam-libs AlmaLinux:10 | All versions | 1.6.1-9.el10_2.1 |
pam AlmaLinux:8 | All versions | 1.3.1-40.el8_10 |
pam-devel AlmaLinux:8 | All versions | 1.3.1-40.el8_10 |
pam AlmaLinux:9 | All versions | 1.5.1-28.el9_8.1 |
pam-devel AlmaLinux:9 | All versions | 1.5.1-28.el9_8.1 |
pam-docs AlmaLinux:9 | All versions | 1.5.1-28.el9_8.1 |
pam Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam-debuginfo Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam-debugsource Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam-devel Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam-libs Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam-libs-debuginfo Red Hat:enterprise_linux:10.2 | All versions | 0:1.6.1-9.el10_2.1 |
pam Red Hat:enterprise_linux:8::baseos | All versions | 0:1.3.1-40.el8_10 |
pam-debuginfo Red Hat:enterprise_linux:8::baseos | All versions | 0:1.3.1-40.el8_10 |
pam-debugsource Red Hat:enterprise_linux:8::baseos | All versions | 0:1.3.1-40.el8_10 |
pam-devel Red Hat:enterprise_linux:8::baseos | All versions | 0:1.3.1-40.el8_10 |
pam-debuginfo Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-27.el9_8.1 |
pam-debuginfo Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-28.el9_8.1 |
pam-debugsource Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-27.el9_8.1 |
pam-debugsource Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-28.el9_8.1 |
pam-devel Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-27.el9_8.1 |
pam-devel Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-28.el9_8.1 |
pam-docs Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-27.el9_8.1 |
pam-docs Red Hat:enterprise_linux:9::appstream | All versions | 0:1.5.1-28.el9_8.1 |
pam Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-27.el9_8.1 |
pam Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-28.el9_8.1 |
pam-debuginfo Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-27.el9_8.1 |
pam-debuginfo Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-28.el9_8.1 |
pam-debugsource Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-27.el9_8.1 |
pam-debugsource Red Hat:enterprise_linux:9::baseos | All versions | 0:1.5.1-28.el9_8.1 |
pam Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam-debuginfo Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam-debugsource Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam-devel Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam-libs Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam-libs-debuginfo Red Hat:enterprise_linux_eus:10.0 | All versions | 0:1.6.1-8.el10_0.1 |
pam Red Hat:hummingbird:1 | All versions | 0:1.7.2-1.1.hum1 |
pam Red Hat:hummingbird:1 | All versions | 0:1.7.2-2.2.hum1 |
How do I fix CVE-2026-54411?
Apply the vendor's patch.
Is CVE-2026-54411 being exploited?
There is no known exploitation of CVE-2026-54411 in the wild and no public exploit code.
Sources
Also known as ALSA-2026:56131, ALSA-2026:59379, ALSA-2026:64815, AZL-90093, CLSA-2026-1788971665, CLSA-2026-1789472351 and 39 more.