CVE-2026-11837

Summary

A local privilege escalation vulnerability was found in the ansible.posix authorized_key module. The module's keyfile() function uses os.chown() instead of os.lchown() and opens files without O_NOFOLLOW when managing SSH authorized keys. An unprivileged local user can pre-stage symbolic links in their ~/.ssh directory to redirect file ownership changes to arbitrary system paths when an operator runs the authorized_key task as root, leading to local privilege escalation.

Affected Software

Weaknesses

• CWE-59: Improper Link Resolution Before File Access ('Link Following')

Workarounds

The following practices would help for avoiding exposure and mitigate this flaw:

1. Do not run the ansible.posix authorized_key module with elevated privileges against untrusted user accounts.
2. Validate that target user home directories do not contain unexpected symbolic links before running playbooks.

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: total

ansible-collection-ansible-posix: ansible.posix authorized_key: local privilege escalation via symlink-following chown

Additional References

• https://access.redhat.com/security/cve/CVE-2026-11837
• https://bugzilla.redhat.com/show_bug.cgi?id=2487424
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-11837.json

References

• https://access.redhat.com/security/cve/CVE-2026-11837
• https://bugzilla.redhat.com/show_bug.cgi?id=2487424

• ←Previous
• Next→