A vulnerability in the zip archive parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper boundary checks for content in zip files during scanning, which may result in an out-of-bounds write condition. An attacker could exploit this vulnerability by submitting a crafted zip file for scanning. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.
CVE-2026-20337
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.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- 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 computedSeverity75% × 45%Exploitation0% × 40%Automatability100% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 29%
- KEV
- Not listed
Published
August 7, 2026
Last Modified
August 11, 2026
Advisory Details (1)
Auto-updated Aug 7, 2026ClamAV Vulnerabilities Affecting Cisco Products: August 2026
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-clamav-WuuvVd26Vendor Advisories for CVE-2026-20337(3)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-20337Microsoft Security Response Center (MSRC)High
ClamAV ZIP File Format Processing Memory Corruption Vulnerability
- GHSA-rhg3-hwfw-hp7pGitHub Security AdvisoriesHigh
A vulnerability in the zip archive parser of ClamAV could allow an unauthenticated, remote...
- cisco-sa-clamav-WuuvVd26Cisco PSIRT openVulnHigh
ClamAV Vulnerabilities Affecting Cisco Products: August 2026
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 26× 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.
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-20 22:34 UTCGHSA enrichment
- 2026-08-20 09:39 UTCGHSA enrichment
- 2026-08-19 20:45 UTCEG score recompute
- 2026-08-19 20:45 UTCGHSA enrichment
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-19 07:50 UTCGHSA enrichment
- 2026-08-18 18:53 UTCEG score recompute
- 2026-08-18 18:53 UTCGHSA enrichment
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-18 05:58 UTCGHSA enrichment
- 2026-08-17 17:03 UTCEG score recompute
- 2026-08-17 17:03 UTCGHSA enrichment
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 04:09 UTCGHSA enrichment
- 2026-08-16 15:14 UTCEG score recompute
- 2026-08-16 15:14 UTCGHSA enrichment
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 02:20 UTCEG score recompute
- 2026-08-16 02:20 UTCGHSA enrichment
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 13:26 UTCEG score recompute
- 2026-08-15 13:26 UTCGHSA enrichment
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-15 00:31 UTCGHSA enrichment
Show 31 moreShow fewer
- 2026-08-14 11:36 UTCGHSA enrichment
- 2026-08-13 22:42 UTCEG score recompute
- 2026-08-13 22:42 UTCGHSA enrichment
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 09:47 UTCGHSA enrichment
- 2026-08-12 20:53 UTCEG score recompute
- 2026-08-12 20:53 UTCGHSA enrichment
- 2026-08-12 13:50 UTCEPSS rescore
- 2026-08-12 07:59 UTCGHSA enrichment
- 2026-08-11 19:04 UTCGHSA enrichment
- 2026-08-11 13:48 UTCEG score recompute
- 2026-08-11 13:48 UTCGHSA enrichment
- 2026-08-11 13:42 UTCEPSS rescore
- 2026-08-11 00:53 UTCEG score recompute
- 2026-08-11 00:53 UTCGHSA enrichment
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 11:59 UTCGHSA enrichment
- 2026-08-09 23:05 UTCEG score recompute
- 2026-08-09 23:05 UTCGHSA enrichment
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 10:11 UTCGHSA enrichment
- 2026-08-08 21:17 UTCEG score recompute
- 2026-08-08 21:17 UTCGHSA enrichment
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 08:23 UTCGHSA enrichment
- 2026-08-07 19:28 UTCEG score recompute
- 2026-08-07 19:28 UTCGHSA enrichment
- 2026-08-07 18:29 UTCEG score recompute
- 2026-08-07 17:25 UTCEG score recompute
- 2026-08-07 16:47 UTCEG score recompute
- 2026-08-07 16:47 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-20337?
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Dependency Blast Radius
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