Memory corruption in upx
Priority LOW 31CWE-119Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
A flaw was found in upx canPack in p_lx_elf.cpp in UPX 3.96. This flaw allows attackers to cause a denial of service (SEGV or buffer overflow and application crash) or possibly have unspecified other impacts via a crafted ELF. The highest threat from this vulnerability is to system availability.
Why it matters now
EPSS 0.00751 55th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | upx | UPX 3.96 | — | No fix listed | CNA |
- upx Vendor— Affected UPX 3.96 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2021-20285
- 2026-10-03 Alias added: GHSA-9235-qgm5-877x
References
More Upx vulnerabilities
- TI-2021-19310 Memory corruption in upx CVSS 3.1HIGH 7.5
- TI-2021-19309 Memory corruption in upx CVSS 3.1HIGH 7.5
- TI-2021-19308 Memory corruption in upx CVSS 3.1HIGH 7.5
- TI-2021-19307 Memory corruption in upx CVSS 3.1HIGH 7.5
- TI-2021-19306 Memory corruption in upx CVSS 3.1HIGH 7.5
- TI-2021-19305 Memory corruption in upx CVSS 3.1HIGH 7.5
Sources
- CVE-2021-20285 · CVE Program
- CVE-2021-20285 · NVD
- FIRST EPSS
- GHSA-9235-qgm5-877x · GitHub Advisory Database · CC BY 4.0
- CVE-2021-20285 · 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