CVE-2026-56391

MEDIUMNVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 97% of all CVEs by exploit prediction. 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, nvd
Trending — Patch released this week
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: None knownExposed: 0

A fix is available — apply it.

GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters by repeatedly processing a fixed pointer instead of advancing through the input, resulting in an inflated length value. This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input.

When running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure.

This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity61% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
3%
KEV
Not listed

Published

July 24, 2026

Last Modified

August 26, 2026

Advisory Details (3)

Auto-updated Jul 24, 2026
No patch confirmed yet.
generic

uniq: fix read overrun with -w - coreutils.git - GNU coreutils

https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371
generic

coreutils.git - GNU coreutils

https://git.savannah.gnu.org/cgit/coreutils.git/
generic

Vulnerabilities in GNU coreutils software | CERT Polska

https://cert.pl/en/posts/2026/07/CVE-2026-56391

Vendor Advisories for CVE-2026-56391(2)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntugnu-coreutils (9.7-3ubuntu2.1) @ resolute2026-09-20ubuntu
redhatcoreutils-0:9.5-8.el10_2.12026-09-16redhat
redhatcoreutils-main-9.11-5.1.hum12026-07-27redhat

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
coreutils8.32-4 ... 9.7-3 (14 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
coreutils9.1-1 ... 9.7-3 (12 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
coreutils9.10-1, 9.7-3——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
coreutils9.10-1, 9.7-3——

Weakness Classification(1)

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

Additional Vendor Advisories

(2)

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 16× in last 7d / 79× 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 180 total refreshes for this CVE.

  1. 2026-09-20 20:16 UTCEPSS rescore
  2. 2026-09-20 01:44 UTCEG score recompute
  3. 2026-09-20 01:44 UTCVendor advisory
  4. 2026-09-20 01:44 UTCGHSA enrichment
  5. 2026-09-18 19:28 UTCEPSS rescore
  6. 2026-09-18 03:02 UTCEG score recompute
  7. 2026-09-18 03:02 UTCVendor advisory
  8. 2026-09-18 03:02 UTCGHSA enrichment
  9. 2026-09-17 19:31 UTCEPSS rescore
  10. 2026-09-16 14:08 UTCEPSS rescore
  11. 2026-09-16 11:59 UTCVendor advisory
  12. 2026-09-16 11:59 UTCGHSA enrichment
  13. 2026-09-15 09:42 UTCEG score recompute
  14. 2026-09-15 09:42 UTCVendor advisory
  15. 2026-09-15 09:42 UTCGHSA enrichment
  16. 2026-09-15 03:11 UTCEPSS rescore
  17. 2026-09-13 22:20 UTCEG score recompute
  18. 2026-09-13 22:20 UTCVendor advisory
  19. 2026-09-13 22:19 UTCGHSA enrichment
  20. 2026-09-13 16:47 UTCEPSS rescore
  21. 2026-09-12 19:56 UTCEG score recompute
  22. 2026-09-12 19:56 UTCVendor advisory
  23. 2026-09-12 19:56 UTCGHSA enrichment
  24. 2026-09-11 17:48 UTCEG score recompute
  25. 2026-09-11 17:48 UTCVendor advisory
Show 75 more
  1. 2026-09-11 17:48 UTCGHSA enrichment
  2. 2026-09-10 14:54 UTCEG score recompute
  3. 2026-09-10 14:54 UTCVendor advisory
  4. 2026-09-10 14:54 UTCGHSA enrichment
  5. 2026-09-10 09:35 UTCEPSS rescore
  6. 2026-09-09 08:51 UTCEG score recompute
  7. 2026-09-09 08:51 UTCVendor advisory
  8. 2026-09-09 08:51 UTCGHSA enrichment
  9. 2026-09-08 22:01 UTCEPSS rescore
  10. 2026-09-07 21:27 UTCEG score recompute
  11. 2026-09-07 21:27 UTCVendor advisory
  12. 2026-09-07 21:27 UTCGHSA enrichment
  13. 2026-09-07 16:01 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-05 19:26 UTCEG score recompute
  16. 2026-09-05 19:26 UTCVendor advisory
  17. 2026-09-05 19:26 UTCGHSA enrichment
  18. 2026-09-04 12:56 UTCVendor advisory
  19. 2026-09-04 12:56 UTCGHSA enrichment
  20. 2026-09-01 23:19 UTCEG score recompute
  21. 2026-09-01 23:19 UTCVendor advisory
  22. 2026-09-01 23:19 UTCGHSA enrichment
  23. 2026-09-01 13:54 UTCEPSS rescore
  24. 2026-09-01 04:40 UTCEPSS rescore
  25. 2026-08-31 02:30 UTCEG score recompute
  26. 2026-08-31 02:30 UTCVendor advisory
  27. 2026-08-31 02:30 UTCGHSA enrichment
  28. 2026-08-30 19:17 UTCEPSS rescore
  29. 2026-08-30 01:22 UTCEPSS rescore
  30. 2026-08-30 00:21 UTCEG score recompute
  31. 2026-08-30 00:21 UTCVendor advisory
  32. 2026-08-30 00:21 UTCGHSA enrichment
  33. 2026-08-28 21:42 UTCEPSS rescore
  34. 2026-08-27 21:07 UTCEG score recompute
  35. 2026-08-27 21:07 UTCVendor advisory
  36. 2026-08-27 21:07 UTCGHSA enrichment
  37. 2026-08-27 14:25 UTCEPSS rescore
  38. 2026-08-26 16:20 UTCEG score recompute▲ 1.50
  39. 2026-08-26 16:20 UTCVendor advisory
  40. 2026-08-26 16:20 UTCGHSA enrichment
  41. 2026-08-26 16:17 UTCNVD updateCVSS v3 → 6.1
  42. 2026-08-26 14:46 UTCEPSS rescore
  43. 2026-08-25 20:15 UTCEG score recompute
  44. 2026-08-25 20:15 UTCVendor advisory
  45. 2026-08-25 20:15 UTCGHSA enrichment
  46. 2026-08-25 13:49 UTCEPSS rescore
  47. 2026-08-24 18:07 UTCEG score recompute
  48. 2026-08-24 18:07 UTCVendor advisory
  49. 2026-08-24 18:07 UTCGHSA enrichment
  50. 2026-08-23 15:49 UTCVendor advisory
  51. 2026-08-23 15:49 UTCGHSA enrichment
  52. 2026-08-22 13:41 UTCEG score recompute
  53. 2026-08-22 13:41 UTCVendor advisory
  54. 2026-08-22 13:41 UTCGHSA enrichment
  55. 2026-08-21 23:49 UTCEPSS rescore
  56. 2026-08-21 11:33 UTCEG score recompute
  57. 2026-08-21 11:33 UTCVendor advisory
  58. 2026-08-21 11:33 UTCGHSA enrichment
  59. 2026-08-20 22:55 UTCEPSS rescore
  60. 2026-08-20 09:25 UTCEG score recompute
  61. 2026-08-20 09:25 UTCVendor advisory
  62. 2026-08-20 09:25 UTCGHSA enrichment
  63. 2026-08-19 17:04 UTCEPSS rescore
  64. 2026-08-19 07:17 UTCEG score recompute
  65. 2026-08-19 07:17 UTCVendor advisory
  66. 2026-08-19 07:17 UTCGHSA enrichment
  67. 2026-08-18 13:48 UTCEPSS rescore
  68. 2026-08-18 05:06 UTCEG score recompute
  69. 2026-08-18 05:06 UTCVendor advisory
  70. 2026-08-18 05:06 UTCGHSA enrichment
  71. 2026-08-17 13:47 UTCEPSS rescore
  72. 2026-08-17 02:57 UTCEG score recompute
  73. 2026-08-17 02:57 UTCVendor advisory
  74. 2026-08-17 02:57 UTCGHSA enrichment
  75. 2026-08-16 14:56 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Same vendor

2 shown

redhat:RHSA-2026:67886 · ubuntu:USN-8697-1

Frequently asked(5)

What is CVE-2026-56391?
CVE-2026-56391 is a medium vulnerability published on July 24, 2026. GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters by repeatedly processing a fixed pointer instead of advancing through the input,…
When was CVE-2026-56391 disclosed?
CVE-2026-56391 was first published in the National Vulnerability Database on July 24, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56391 actively exploited?
CVE-2026-56391 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 96.9% of all scored CVEs.
What is the CVSS score of CVE-2026-56391?
CVE-2026-56391 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-56391?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56391, 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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