CVE-2026-20347

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM 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 — 4 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: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

A vulnerability in the Mach-O 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 Mach-O files during scanning, which may result in an out-of-bounds buffer read. An attacker could exploit this vulnerability by submitting a crafted Mach-O file 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
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
37th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 7, 2026

Last Modified

August 11, 2026

Advisory Details (1)

Auto-updated Aug 7, 2026
🔬 Proof of concept available. Patch available.
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-2026-20347(3)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntulibclamav12 (1.5.4+dfsg-0ubuntu0.24.04.1) @ noble2026-10-04ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
clamav0.103.10+dfsg-0+deb11u1 ... 1.4.5+dfsg-3 (57 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
clamav1.0.1+dfsg-2 ... 1.4.6+dfsg-1 (37 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
clamav1.4.3+dfsg-1 ... 1.4.6+dfsg-1 (8 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
clamav1.4.3+dfsg-1 ... 1.4.5+dfsg-3 (7 versions)
  • every version up to 1.4.6+dfsg-1: fixed in 1.4.6+dfsg-1
—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 24× in last 7d / 125× 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.

Showing the most recent 100 of 258 total refreshes for this CVE.

  1. 2026-10-04 23:21 UTCEPSS rescore
  2. 2026-10-04 23:01 UTCVendor advisory
  3. 2026-10-04 23:01 UTCGHSA enrichment
  4. 2026-10-04 05:43 UTCEG score recompute
  5. 2026-10-04 05:43 UTCVendor advisory
  6. 2026-10-04 05:43 UTCGHSA enrichment
  7. 2026-10-03 01:00 UTCEG score recompute
  8. 2026-10-03 01:00 UTCVendor advisory
  9. 2026-10-03 01:00 UTCGHSA enrichment
  10. 2026-10-02 09:33 UTCEG score recompute
  11. 2026-10-02 09:33 UTCVendor advisory
  12. 2026-10-02 09:33 UTCGHSA enrichment
  13. 2026-10-01 19:49 UTCEPSS rescore
  14. 2026-10-01 11:13 UTCVendor advisory
  15. 2026-10-01 11:13 UTCGHSA enrichment
  16. 2026-09-30 22:55 UTCEG score recompute
  17. 2026-09-30 22:55 UTCVendor advisory
  18. 2026-09-30 22:55 UTCGHSA enrichment
  19. 2026-09-30 15:03 UTCEPSS rescore
  20. 2026-09-29 15:21 UTCEPSS rescore
  21. 2026-09-29 05:46 UTCEG score recompute
  22. 2026-09-29 05:46 UTCVendor advisory
  23. 2026-09-29 05:46 UTCGHSA enrichment
  24. 2026-09-28 13:51 UTCEPSS rescore
  25. 2026-09-28 05:21 UTCVendor advisory
Show 75 more
  1. 2026-09-28 05:21 UTCGHSA enrichment
  2. 2026-09-27 17:10 UTCEG score recompute
  3. 2026-09-27 17:10 UTCVendor advisory
  4. 2026-09-27 17:10 UTCGHSA enrichment
  5. 2026-09-27 13:47 UTCEPSS rescore
  6. 2026-09-26 15:58 UTCEPSS rescore
  7. 2026-09-26 00:26 UTCEPSS rescore
  8. 2026-09-25 04:15 UTCEG score recompute
  9. 2026-09-25 04:15 UTCVendor advisory
  10. 2026-09-25 04:15 UTCGHSA enrichment
  11. 2026-09-24 14:03 UTCEPSS rescore
  12. 2026-09-24 01:58 UTCEG score recompute
  13. 2026-09-24 01:58 UTCVendor advisory
  14. 2026-09-24 01:58 UTCGHSA enrichment
  15. 2026-09-23 13:47 UTCVendor advisory
  16. 2026-09-23 13:46 UTCGHSA enrichment
  17. 2026-09-23 01:12 UTCEG score recompute
  18. 2026-09-23 01:12 UTCVendor advisory
  19. 2026-09-23 01:12 UTCGHSA enrichment
  20. 2026-09-22 12:54 UTCVendor advisory
  21. 2026-09-22 12:54 UTCGHSA enrichment
  22. 2026-09-22 00:42 UTCEG score recompute
  23. 2026-09-22 00:42 UTCVendor advisory
  24. 2026-09-22 00:42 UTCGHSA enrichment
  25. 2026-09-21 12:04 UTCEG score recompute
  26. 2026-09-21 12:04 UTCVendor advisory
  27. 2026-09-21 12:03 UTCGHSA enrichment
  28. 2026-09-20 20:15 UTCEPSS rescore
  29. 2026-09-20 10:55 UTCVendor advisory
  30. 2026-09-20 10:55 UTCGHSA enrichment
  31. 2026-09-19 20:11 UTCEG score recompute
  32. 2026-09-19 20:11 UTCVendor advisory
  33. 2026-09-19 20:11 UTCGHSA enrichment
  34. 2026-09-19 06:40 UTCEG score recompute
  35. 2026-09-19 06:40 UTCVendor advisory
  36. 2026-09-19 06:40 UTCGHSA enrichment
  37. 2026-09-18 19:27 UTCEPSS rescore
  38. 2026-09-18 17:34 UTCVendor advisory
  39. 2026-09-18 17:34 UTCGHSA enrichment
  40. 2026-09-18 03:22 UTCEG score recompute
  41. 2026-09-18 03:22 UTCVendor advisory
  42. 2026-09-18 03:22 UTCGHSA enrichment
  43. 2026-09-17 15:10 UTCVendor advisory
  44. 2026-09-17 15:10 UTCGHSA enrichment
  45. 2026-09-17 00:53 UTCEG score recompute
  46. 2026-09-17 00:53 UTCVendor advisory
  47. 2026-09-17 00:53 UTCGHSA enrichment
  48. 2026-09-16 14:07 UTCEPSS rescore
  49. 2026-09-16 05:15 UTCEPSS rescore
  50. 2026-09-16 02:50 UTCVendor advisory
  51. 2026-09-16 02:50 UTCGHSA enrichment
  52. 2026-09-15 14:15 UTCEG score recompute
  53. 2026-09-15 14:15 UTCVendor advisory
  54. 2026-09-15 14:15 UTCGHSA enrichment
  55. 2026-09-15 00:59 UTCVendor advisory
  56. 2026-09-15 00:59 UTCGHSA enrichment
  57. 2026-09-14 08:44 UTCVendor advisory
  58. 2026-09-14 08:44 UTCGHSA enrichment
  59. 2026-09-13 20:32 UTCEG score recompute
  60. 2026-09-13 20:32 UTCVendor advisory
  61. 2026-09-13 20:32 UTCGHSA enrichment
  62. 2026-09-13 16:47 UTCEPSS rescore
  63. 2026-09-13 08:21 UTCVendor advisory
  64. 2026-09-13 08:20 UTCGHSA enrichment
  65. 2026-09-12 20:09 UTCEG score recompute
  66. 2026-09-12 20:09 UTCVendor advisory
  67. 2026-09-12 20:09 UTCGHSA enrichment
  68. 2026-09-12 15:01 UTCEPSS rescore
  69. 2026-09-12 07:57 UTCVendor advisory
  70. 2026-09-12 07:57 UTCGHSA enrichment
  71. 2026-09-11 19:34 UTCEG score recompute
  72. 2026-09-11 19:34 UTCVendor advisory
  73. 2026-09-11 19:34 UTCGHSA enrichment
  74. 2026-09-11 14:52 UTCEPSS rescore
  75. 2026-09-11 07:22 UTCGHSA enrichment

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-20347?
CVE-2026-20347 is a high vulnerability published on August 7, 2026. A vulnerability in the Mach-O 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-2026-20347 disclosed?
CVE-2026-20347 was first published 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-2026-20347 actively exploited?
CVE-2026-20347 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-20347?
CVE-2026-20347 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-20347?
A fix for CVE-2026-20347 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-20347 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-20347

Explore →

Is Your Infrastructure Affected by CVE-2026-20347?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs