libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).
Priority LOW 34CWE-416Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.
Summary
libarchive 3.4.1 through 3.5.1 has a use-after-free in copy_string (called from do_uncompress_block and process_block).
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02845 86th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libarchive:libarchive:*:*:*:*:*:*:*:* | 3.4.1 – 3.5.2 | Vulnerable | libarchive |
| cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* | 35 | Vulnerable | Fedoraproject |
| cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:* | before 15.4 | Vulnerable | Apple |
| cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* | before 15.4 | Vulnerable | Apple |
| cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* | before 12.3 | Vulnerable | Apple |
| cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:* | before 8.5 | Vulnerable | Apple |
| cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:* | 8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6 | Vulnerable | Splunk |
| cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:* | 9.1.0 | Vulnerable | Splunk |
- cpe:2.3:a:libarchive:libarchive:*:*:*:*:*:*:*:* Versions 3.4.1 – 3.5.2 Vulnerable ·libarchive
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:* Versions 35 Vulnerable ·Fedoraproject
- cpe:2.3:o:apple:ipados:*:*:*:*:*:*:*:* Versions before 15.4 Vulnerable ·Apple
- cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* Versions before 15.4 Vulnerable ·Apple
- cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:* Versions before 12.3 Vulnerable ·Apple
- cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:* Versions before 8.5 Vulnerable ·Apple
- cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:* Versions 8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6 Vulnerable ·Splunk
- cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:* Versions 9.1.0 Vulnerable ·Splunk
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-36976
- 2026-10-03 Alias added: GHSA-4fxq-mcvv-8fqm
- 2026-11-02 CISA SSVC decision points changed
References
Advisory 10
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libarchive/OSV-2021-557.yaml
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32375
- FEDORA-2022-9bb794c5f5
- https://support.apple.com/kb/HT213183
- https://support.apple.com/kb/HT213182
- https://support.apple.com/kb/HT213193
- 20220314 APPLE-SA-2022-03-14-2 watchOS 8.5
- 20220314 APPLE-SA-2022-03-14-4 macOS Monterey 12.3
- 20220314 APPLE-SA-2022-03-14-1 iOS 15.4 and iPadOS 15.4
- GLSA-202208-26
Sources
- CVE-2021-36976 · CVE Program
- CVE-2021-36976 · NVD
- FIRST EPSS
- GHSA-4fxq-mcvv-8fqm · GitHub Advisory Database · CC BY 4.0
- CVE-2021-36976 · 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