CVE-2026-39243

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-07-10. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

decompress before 4.2.2 allows arbitrary hardlink creation during archive extraction, enabling file read disclosure and file corruption. When processing hardlink entries (type === 'link'), the x.linkname field from the archive is passed directly to fs.link() without validation (index.js line 113). An attacker can craft an archive with a hardlink entry whose linkname is an absolute path to any file on the same filesystem. This creates a hardlink inside the extraction directory that shares the same inode as the target file, enabling both reading and overwriting the original file's content. Hardlinks are limited to files on the same filesystem and cannot target directories.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity55% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
22%
KEV
Not listed

Published

July 9, 2026

Last Modified

July 13, 2026

Advisory Details (2)

Auto-updated Jul 10, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic🟡 PoC Available

[CVE-2026-39243] Arbitrary hardlink creation during extraction → file read disclosure & corruption · Issue #113 · kevva/decompress · GitHub

https://github.com/kevva/decompress/issues/113
generic

GitHub - kevva/decompress: Extracting archives made easy · GitHub

https://github.com/kevva/decompress

Vendor Advisories for CVE-2026-39243(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
redhatdotnet8-0-main-8.0.128-1.1.hum12026-07-10redhat
npmdecompress—ghsa

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.

Data Freshness Timeline

(refreshed 23× in last 7d / 114× 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 162 total refreshes for this CVE.

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

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

Same product

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npm:decompress

Frequently asked(5)

What is CVE-2026-39243?
CVE-2026-39243 is a medium vulnerability published on July 9, 2026. decompress before 4.2.2 allows arbitrary hardlink creation during archive extraction, enabling file read disclosure and file corruption. When processing hardlink entries (type === 'link'), the x.linkname field from the archive is passed directly to fs.link() without validation (index.js line 113).…
When was CVE-2026-39243 disclosed?
CVE-2026-39243 was first published in the National Vulnerability Database on July 9, 2026, with the most recent update on July 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-39243 actively exploited?
CVE-2026-39243 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 77.7% of all scored CVEs.
What is the CVSS score of CVE-2026-39243?
CVE-2026-39243 has a CVSS v3.1 base score of 5.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-39243?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-39243, 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

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