CVE-2026-4426

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-03-19. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation of a field (pz_log2_bs) read from ISO9660 Rock Ridge extensions. A remote attacker can exploit this by supplying a specially crafted ISO file. This can lead to incorrect memory allocation and potential application crashes, resulting in a denial-of-service (DoS) condition.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
22.4%
KEV
Not listed

Published

March 19, 2026

Last Modified

May 3, 2026

Advisory Details (4)

Auto-updated May 3, 2026
Patch available. Sources: redhat.
generic

iso9660: validate pz_log2_bs in parse_rockridge_ZF1() by ElhananHaenel · Pull Request #2897 · libarchive/libarchive · GitHub

https://github.com/libarchive/libarchive/pull/2897
redhat Patch Available

2449010 – (CVE-2026-4426) CVE-2026-4426 libarchive: libarchive: Denial of Service via malformed ISO file processing

https://bugzilla.redhat.com/show_bug.cgi?id=2449010
redhat Patch Available

cve-details

https://access.redhat.com/security/cve/CVE-2026-4426
redhat Patch Available
https://access.redhat.com/errata/RHSA-2026:8944

Vendor Advisories for CVE-2026-4426(2)

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

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibarchive13 (3.1.2-11ubuntu0.16.04.8+esm3) @ xenial2026-06-11ubuntu
redhatlibarchive-main-3.8.7-1.hum12026-04-20redhat

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.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-4426?
CVE-2026-4426 is a medium vulnerability published on March 19, 2026. A flaw was found in libarchive. An Undefined Behavior vulnerability exists in the zisofs decompression logic, caused by improper validation of a field (pzlog2bs) read from ISO9660 Rock Ridge extensions. A remote attacker can exploit this by supplying a specially crafted ISO file. This can lead to…
When was CVE-2026-4426 disclosed?
CVE-2026-4426 was first published in the National Vulnerability Database on March 19, 2026, with the most recent update on May 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-4426 actively exploited?
CVE-2026-4426 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-4426?
CVE-2026-4426 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-4426?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-4426, 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.

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