CVE-2026-20339

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-07. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

A vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in PESpin files during scanning, which may result in an integer overflow. An attacker could exploit this vulnerability by submitting a crafted file that contains PESpin content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

August 7, 2026

Last Modified

August 11, 2026

Advisory Details (1)

Auto-updated Aug 7, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

ClamAV Vulnerabilities Affecting Cisco Products: August 2026

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-WuuvVd26

Vendor Advisories for CVE-2026-20339(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
clamav0.103.10+dfsg-0+deb11u1 ... 1.4.5+dfsg-3 (57 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
clamav1.0.1+dfsg-2 ... 1.4.5+dfsg-3 (36 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
clamav1.4.3+dfsg-1 ... 1.4.5+dfsg-3 (7 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
clamav1.4.3+dfsg-1 ... 1.4.5+dfsg-3 (7 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 28× in last 7d / 56× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-20 07:26 UTCGHSA enrichment
  2. 2026-08-19 19:26 UTCEG score recompute
  3. 2026-08-19 19:26 UTCGHSA enrichment
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 07:26 UTCGHSA enrichment
  6. 2026-08-18 19:26 UTCEG score recompute
  7. 2026-08-18 19:26 UTCGHSA enrichment
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-18 07:24 UTCGHSA enrichment
  10. 2026-08-17 19:24 UTCEG score recompute
  11. 2026-08-17 19:24 UTCGHSA enrichment
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-17 07:05 UTCGHSA enrichment
  14. 2026-08-16 19:06 UTCEG score recompute
  15. 2026-08-16 19:06 UTCGHSA enrichment
  16. 2026-08-16 14:56 UTCEPSS rescore
  17. 2026-08-16 07:06 UTCEG score recompute
  18. 2026-08-16 07:06 UTCGHSA enrichment
  19. 2026-08-16 02:14 UTCEPSS rescore
  20. 2026-08-15 19:07 UTCGHSA enrichment
  21. 2026-08-15 07:07 UTCEG score recompute
  22. 2026-08-15 07:07 UTCGHSA enrichment
  23. 2026-08-15 01:30 UTCEPSS rescore
  24. 2026-08-14 19:07 UTCGHSA enrichment
  25. 2026-08-14 07:08 UTCEG score recompute
Show 31 more
  1. 2026-08-14 07:08 UTCGHSA enrichment
  2. 2026-08-13 22:00 UTCEPSS rescore
  3. 2026-08-13 19:08 UTCGHSA enrichment
  4. 2026-08-13 07:08 UTCGHSA enrichment
  5. 2026-08-12 19:04 UTCEG score recompute
  6. 2026-08-12 19:04 UTCGHSA enrichment
  7. 2026-08-12 13:50 UTCEPSS rescore
  8. 2026-08-12 07:04 UTCGHSA enrichment
  9. 2026-08-11 19:04 UTCEG score recompute
  10. 2026-08-11 19:04 UTCGHSA enrichment
  11. 2026-08-11 13:42 UTCEPSS rescore
  12. 2026-08-11 10:31 UTCEG score recompute
  13. 2026-08-11 10:31 UTCGHSA enrichment
  14. 2026-08-11 00:00 UTCEPSS rescore
  15. 2026-08-10 22:32 UTCGHSA enrichment
  16. 2026-08-10 10:32 UTCGHSA enrichment
  17. 2026-08-09 22:32 UTCEG score recompute
  18. 2026-08-09 22:32 UTCGHSA enrichment
  19. 2026-08-09 13:46 UTCEPSS rescore
  20. 2026-08-09 10:32 UTCGHSA enrichment
  21. 2026-08-08 22:33 UTCEG score recompute
  22. 2026-08-08 22:33 UTCGHSA enrichment
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-08 10:32 UTCGHSA enrichment
  25. 2026-08-07 22:33 UTCEG score recompute
  26. 2026-08-07 22:33 UTCGHSA enrichment
  27. 2026-08-07 21:22 UTCEG score recompute
  28. 2026-08-07 21:22 UTCGHSA enrichment
  29. 2026-08-07 17:25 UTCEG score recompute
  30. 2026-08-07 16:47 UTCEG score recompute
  31. 2026-08-07 16:47 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-20339?
CVE-2026-20339 is a high vulnerability published on August 7, 2026. A vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition or possibly other expanded impacts as a result of memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in…
When was CVE-2026-20339 disclosed?
CVE-2026-20339 was first published in the National Vulnerability Database on August 7, 2026, with the most recent update on August 11, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-20339 actively exploited?
CVE-2026-20339 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.3% of all scored CVEs.
What is the CVSS score of CVE-2026-20339?
CVE-2026-20339 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-20339?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-20339, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-20339

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