CVE
Red Hat Enterprise Linux arbitrary file write in Ansible.posix authorized_key module
- Exploited
- No known exploitation
- Fix
- See vendor advisory
- Who is exposed
- Not reported
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 19/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The authorized_key module in the Ansible.posix collection, as shipped in the rhc-worker-playbook package for Red Hat Enterprise Linux 9 and 10, follows a symlinked parent directory. A local user with low privileges can make a root-run task write or overwrite files in a directory of their choice, which can harm integrity and availability, and this requires an operator to run the task as root.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
A link-following flaw was found in the authorized_key module of the ansible.posix collection, residual to the fix for CVE-2026-11837. That fix guards only the final path component (os.chown with follow_symlinks=False and O_NOFOLLOW in _safe_open_write()). When an unprivileged local user replaces their ~/.ssh directory with a symlink to a directory they do not own, and an operator subsequently runs the authorized_key task as root (a common provisioning pattern), the module resolves its path operations through the symlink: atomic_move() writes the temporary file in the symlink target and renames it to <target>/authorized_keys, creating or overwriting a file in the attacker-chosen directory, and os.chmod(sshdir, 0o700) follows the symlink and changes the target directory's permissions. The written file is chowned to the unprivileged user, so this is not a privilege escalation, but it allows an attacker to create or overwrite files (for example in /etc/apt/apt.conf.d/, which APT reads regardless of file ownership) to cause integrity and availability impacts.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach10/20Shipped in major Linux distributions
- Severity3.9/10CVSS 3.9
- No patch5/5No fixed version listed; see vendor advisory
What would change the score
- Would score about 74 if added to CISA KEV
- Would score about 69 if CISA's SSVC rates exploitation active
- Would score about 41 if advisories confirm default setups are exposed
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-126644 (Ansible.posix: authorized_key module follows a parent-directory symlink allowing writes outside the intended directory), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-126644 (entry last updated 2026-11-12):
Affected:
- Red Hat Red Hat Enterprise Linux 10: version range not reported
- Red Hat Red Hat Enterprise Linux 9: version range not reported
Fixed versions: none listed yet.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-126644 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-126644 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://bugzilla.redhat.com/show_bug.cgi?id=2571732
- https://access.redhat.com/security/cve/CVE-2026-126644
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-126644
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-126644"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- rhc-worker-playbook
Version range not reported
- rhc-worker-playbook
Version range not reported
Evidence 4
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Write-ups · 1
Establishes: Technical detail and context.
- Report
Other links · 1
- Link
Corrections
None so far.
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