Tar: tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape
Priority LOW 19CWE-367Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Partial Red Hat: 6 fixed, 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00104 1st percentileScored 2026-11-07
Fix Partial Red Hat: 6 advisoriesRed Hat: 6 fixed, 4 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | 2:1.35-13.el10_2 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | 2:1.30-13.el8_10 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | 2:1.34-13.el9_8 | Patch available | CNA |
| Red Hat | Red Hat Discovery 2 | — | 1788205779 | Patch available | CNA |
| Red Hat | Red Hat Hardened Images | — | 1.35-9.1.hum1 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1788880445 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1788880464 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1788880456 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1788765051 | Patch available | CNA |
| Red Hat | Red Hat Update Infrastructure 5 | — | 1788880581 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat Hardened Images | — | — | Not affected | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 2:1.35-13.el10_2 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 2:1.30-13.el8_10 Patch available CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 2:1.34-13.el9_8 Patch available CNA
- Red Hat Discovery 2 VendorRed Hat Affected — Fixed in 1788205779 Patch available CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in 1.35-9.1.hum1 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1788880445 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1788880464 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1788880456 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1788765051 Patch available CNA
- Red Hat Update Infrastructure 5 VendorRed Hat Affected — Fixed in 1788880581 Patch available CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 5 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:* | 1.35 | Vulnerable | GNU |
| cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:* | 4.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
- cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:* Versions 1.35 Vulnerable ·GNU
- cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:* Versions 4.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
Remediation
Red Hat 6 advisories
- RHSA-2026:70390 Released 2026-09-22 · Red Hat rating Moderatetar security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) tar-2:1.30-13.el8_10
- RHSA-2026:66018 Released 2026-09-09 · Red Hat rating ImportantRed Hat Update Infrastructure 5.3 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
- RHSA-2026:61586 Released 2026-09-01 · Red Hat rating Moderatetar security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 10) tar-2:1.35-13.el10_2
Show 3 more Red Hat advisories
- RHSA-2026:61783 Released 2026-08-31 · Red Hat rating ImportantA Subscription Management tool for finding and reporting Red Hat product usage
- Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
- RHSA-2026:61581 Released 2026-08-31 · Red Hat rating Moderatetar security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 9) tar-2:1.34-13.el9_8
- RHSA-2026:49361 Released 2026-08-01 · Red Hat rating ModerateRed Hat Hardened Images RPMs Security Update
- Red Hat Hardened Images tar-2:1.35-9.1.hum1@aarch64, tar-2:1.35-9.1.hum1@src, tar-2:1.35-9.1.hum1@x86_64
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
| Red Hat Discovery 2 | Fixed | RHSA-2026:61783 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:61586 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:70390 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:61581 |
| Red Hat Hardened Images | Fixed | RHSA-2026:49361 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:66018 |
Not affected: 2 products
- Red Hat Discovery 2
- Red Hat Hardened Images
Timeline
- 2026-10-02 Threatist record created from CVE-2026-18477
- 2026-10-03 Alias added: GHSA-v7fx-gjvh-347c
- 2026-10-30 Affected versions changed · CNA
- 2026-10-31 Affected versions changed · Red Hat
References
More Red Hat Enterprise Linux vulnerabilities
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2018-10530 Code injection in [UNKNOWN] RichFaces KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2026-18477 · CVE Program
- CVE-2026-18477 · NVD
- FIRST EPSS
- GHSA-v7fx-gjvh-347c · GitHub Advisory Database · CC BY 4.0
- CVE-2026-18477 · Red Hat security data · CC BY 4.0
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