Memory leak in tar
Priority LOW 18CWE-401Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-401.
Summary
A flaw was found in the src/list.c of tar 1.33 and earlier. This flaw allows an attacker who can submit a crafted input file to tar to cause uncontrolled consumption of memory. The highest threat from this vulnerability is to system availability.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01096 65th percentileScored 2026-11-07
Fix Deferred Red Hat: fix deferred
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 |
|---|---|---|---|---|---|
| — | tar | up to 1.33 | — | No fix listed | CNA |
- tar Vendor— Affected up to 1.33 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
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 Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20193
- 2026-10-03 Alias added: GHSA-mwq4-jmcc-2cx4
- 2026-10-08 CISA SSVC decision points changed
References
More GNU Tar vulnerabilities
- TI-2019-07294 pax_decode_header in sparse.c in GNU Tar before 1.32 had a NULL pointer dereference when… CVSS 3.1HIGH 7.5
- TI-2016-05412 Directory traversal vulnerability in the safer_name_suffix function in GNU tar 1.14… CVSS 3.1HIGH 7.5
- TI-2022-23920 GNU Tar through 1.34 has a one-byte out-of-bounds read that results in use of… CVSS 3.1MEDIUM 5.5
- TI-2025-28801 Path traversal in GNU Tar CVSS 3.1MEDIUM 4.1
- TI-2005-02406 Tar 1.15.1 does not properly warn the user when extracting setuid or setgid files, which… CVSS 2.0HIGH 10.0
- TI-2007-04334 Buffer overflow in the safer_name_suffix function in GNU tar has unspecified attack… CVSS 2.0HIGH 7.5
Sources
- CVE-2021-20193 · CVE Program
- CVE-2021-20193 · NVD
- FIRST EPSS
- GHSA-mwq4-jmcc-2cx4 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-20193 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences