CVE-2026-18508

MEDIUMPre-NVD 4.44.4—
EchelonGraph scoreHIGH confidence

Score 4.4 from GitHub Security Advisory published 2026-08-03. a secondary CVSS source baseline 4.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
4.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.4Exploit: None knownExposed: 0

A fix is available — apply it.

A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.

CVSS v3
4.4
EG Score
4.4(high)
EG Risk
20(Track)
EG Risk 20/100SSVC: 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
Severity44% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

August 3, 2026

Last Modified

August 18, 2026

Advisory Details (2)

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

Bug Access Denied

https://bugzilla.redhat.com/show_bug.cgi?id=2509843
redhat Patch Available

CVE-2026-18508 - Red Hat Customer Portal

Affected: Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to a

https://access.redhat.com/security/cve/CVE-2026-18508

Vendor Advisories for CVE-2026-18508(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 / EcosystemFixed in / PatchReleasedSource
redhattar-main-1.35-9.2.hum12026-08-05redhat

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 rangeFixed inDependents
tar1.34+dfsg-1 ... 1.35+dfsg-4 (11 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
tar1.34+dfsg-1.2 ... 1.35+dfsg-4 (9 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
tar1.35+dfsg-3.1, 1.35+dfsg-4——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
tar1.35+dfsg-3.1, 1.35+dfsg-4——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 26× in last 7d / 68× 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. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 14:21 UTCEG score recompute
  3. 2026-08-20 14:21 UTCVendor advisory
  4. 2026-08-20 14:21 UTCGHSA enrichment
  5. 2026-08-19 17:03 UTCEPSS rescore
  6. 2026-08-19 15:21 UTCVendor advisory
  7. 2026-08-19 15:21 UTCGHSA enrichment
  8. 2026-08-18 16:49 UTCEG score recompute
  9. 2026-08-18 16:49 UTCVendor advisory
  10. 2026-08-18 16:49 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 19:36 UTCEG score recompute
  13. 2026-08-17 19:36 UTCVendor advisory
  14. 2026-08-17 19:36 UTCGHSA enrichment
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-16 20:50 UTCEG score recompute
  17. 2026-08-16 20:50 UTCVendor advisory
  18. 2026-08-16 20:50 UTCGHSA enrichment
  19. 2026-08-16 14:56 UTCEPSS rescore
  20. 2026-08-16 02:14 UTCEPSS rescore
  21. 2026-08-15 22:30 UTCEG score recompute
  22. 2026-08-15 22:30 UTCVendor advisory
  23. 2026-08-15 22:30 UTCGHSA enrichment
  24. 2026-08-15 01:30 UTCEPSS rescore
  25. 2026-08-15 00:08 UTCVendor advisory
Show 43 more
  1. 2026-08-15 00:08 UTCGHSA enrichment
  2. 2026-08-14 01:48 UTCEG score recompute
  3. 2026-08-14 01:48 UTCVendor advisory
  4. 2026-08-14 01:48 UTCGHSA enrichment
  5. 2026-08-13 22:00 UTCEPSS rescore
  6. 2026-08-13 03:27 UTCEG score recompute
  7. 2026-08-13 03:27 UTCVendor advisory
  8. 2026-08-13 03:27 UTCGHSA enrichment
  9. 2026-08-12 13:50 UTCEPSS rescore
  10. 2026-08-12 05:07 UTCEG score recompute
  11. 2026-08-12 05:07 UTCVendor advisory
  12. 2026-08-12 05:07 UTCGHSA enrichment
  13. 2026-08-11 13:42 UTCEPSS rescore
  14. 2026-08-11 06:46 UTCEG score recompute
  15. 2026-08-11 06:46 UTCVendor advisory
  16. 2026-08-11 06:46 UTCGHSA enrichment
  17. 2026-08-11 00:00 UTCEPSS rescore
  18. 2026-08-10 08:26 UTCVendor advisory
  19. 2026-08-10 08:26 UTCGHSA enrichment
  20. 2026-08-09 10:06 UTCEG score recompute
  21. 2026-08-09 10:06 UTCVendor advisory
  22. 2026-08-09 10:06 UTCGHSA enrichment
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-08 11:46 UTCEG score recompute
  25. 2026-08-08 11:46 UTCVendor advisory
  26. 2026-08-08 11:46 UTCGHSA enrichment
  27. 2026-08-07 13:26 UTCEG score recompute
  28. 2026-08-07 13:25 UTCGHSA enrichment
  29. 2026-08-07 12:48 UTCEG score recompute
  30. 2026-08-07 12:48 UTCGHSA enrichment
  31. 2026-08-07 11:01 UTCEG score recompute
  32. 2026-08-07 11:01 UTCGHSA enrichment
  33. 2026-08-06 13:46 UTCEPSS rescore
  34. 2026-08-06 12:41 UTCEG score recompute
  35. 2026-08-06 12:41 UTCGHSA enrichment
  36. 2026-08-05 19:17 UTCEPSS rescore
  37. 2026-08-05 14:21 UTCGHSA enrichment
  38. 2026-08-04 16:00 UTCEG score recompute
  39. 2026-08-04 16:00 UTCGHSA enrichment
  40. 2026-08-04 15:10 UTCEPSS rescore
  41. 2026-08-03 16:36 UTCEG score recompute
  42. 2026-08-03 15:28 UTCEG score recompute
  43. 2026-08-03 15:28 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-18508?
CVE-2026-18508 is a medium vulnerability published on August 3, 2026. A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary…
When was CVE-2026-18508 disclosed?
CVE-2026-18508 was first published in the National Vulnerability Database on August 3, 2026, with the most recent update on August 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18508 actively exploited?
CVE-2026-18508 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 96.5% of all scored CVEs.
What is the CVSS score of CVE-2026-18508?
CVE-2026-18508 has a CVSS v3 base score of 4.4 (NVD).
How do I remediate CVE-2026-18508?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18508, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-18508

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