RHSA-2026:49361
A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue.
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | tar-2:1.35-9.1.hum1@aarch64 as a component of Red Hat Hardened Images | 1.35-9.1.hum1 |
| Red Hat | tar-2:1.35-9.1.hum1@x86_64 as a component of Red Hat Hardened Images | 1.35-9.1.hum1 |
| Red Hat | tar-2:1.35-9.1.hum1@src as a component of Red Hat Hardened Images | 1.35-9.1.hum1 |
Timeline
- Aug 1, 2026 CVE Published
- Oct 22, 2026 CVE Updated
- Oct 22, 2026 Distribution Patch
- Oct 22, 2026 Distribution Patch
- Oct 22, 2026 Security Advisory
- Oct 22, 2026 Security Advisory
References
- https://access.redhat.com/errata/RHSA-2026:49361 advisory
- https://access.redhat.com/security/cve/CVE-2026-18477 advisory
- https://access.redhat.com/security/updates/classification/ advisory
- https://images.redhat.com/ advisory
- https://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_49361.json advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2509735 issue
- https://www.cve.org/CVERecord?id=CVE-2026-18477 advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-18477 advisory