CVE-2026-66484

MEDIUMPre-NVD 4.64.6—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.6 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (8th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
4.6EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.6Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files.

This issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad

CVSS v3
4.6
EG Score
4.6MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100CISA 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
Severity46% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or 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
0.2%
EPSS %ILE
8th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or 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 (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). 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 10, 2026

Last Modified

August 28, 2026

Advisory Details (1)

Auto-updated Aug 10, 2026
Patch available.
generic

Vulnerabilities in GNU cpio software | CERT Polska

https://cert.pl/en/posts/2026/08/CVE-2026-66484

Vendor Advisories for CVE-2026-66484(3)

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 / EcosystemFix (by version range) / PatchReleasedSource
ubuntucpio-win32 (2.13+dfsg-2ubuntu0.4+esm1) @ focal2026-10-05ubuntu
redhatcpio-main-2.15-10.1.hum12026-08-13redhat

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
cpio2.13+dfsg-7.1, 2.14+dfsg-1, 2.15+dfsg-1, 2.15+dfsg-2, 2.15+dfsg-2.1
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
cpio2.15+dfsg-2, 2.15+dfsg-2.1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
cpio2.15+dfsg-2, 2.15+dfsg-2.1
  • every version on: no fix on record
—

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 21× in last 7d / 88× 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 170 total refreshes for this CVE.

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

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ubuntu:USN-8704-1

Frequently asked(5)

What is CVE-2026-66484?
CVE-2026-66484 is a medium vulnerability published on August 10, 2026. GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the linktoname function without…
When was CVE-2026-66484 disclosed?
CVE-2026-66484 was first published on August 10, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66484 actively exploited?
CVE-2026-66484 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (8th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-66484?
CVE-2026-66484 has a CVSS base score of 4.6 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-66484?
A fix for CVE-2026-66484 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-66484 are linked in the Vendor Advisories panel on this page.

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