CVE-2026-27456

MEDIUMNVD 4.74.7—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.7 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 98% 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
Elevated
4.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.7Exploit: Elevated riskExposed: 0

A fix is available — apply it.

util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink pointing to any root-owned file or device during the race window, causing the SUID binary to open and mount it as root. Exploitation requires an /etc/fstab entry with user,loop options whose path points to a directory where the attacker has write permission, and that /usr/bin/mount has the SUID bit set (the default configuration on virtually all Linux distributions). The impact is unauthorized read access to root-protected files and block devices, including backup images, disk volumes, and any file containing a valid filesystem. This issue has been patched in version 2.41.4.

CVSS v3
4.7
EG Score
4.7(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: 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
Severity47% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
2%
KEV
Not listed

Published

April 3, 2026

Last Modified

July 24, 2026

Advisory Details (2)

Auto-updated Jul 26, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

TOCTOU Race Condition in util-linux mount(8) - Loop Device Setup · Advisory · util-linux/util-linux · GitHub

https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g
github_commit

commit 5e390467b26a (util-linux/util-linux)

Fix landed in util-linux/util-linux commit 5e390467b26a — awaiting tagged release

https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4

Vendor Advisories for CVE-2026-27456(2)

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
redhatutil-linux-main-2.42-7.1.hum12026-04-09redhat

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

(6 across 6 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
util-linux—2.41.4-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
util-linux—2.41.4-r0—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
util-linux2.36.1-8 ... 2.42~rc2-1 (140 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
util-linux2.38.1-5 ... 2.42~rc2-1 (116 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
util-linux2.41-5 ... 2.42~rc2-1 (31 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
util-linux2.41-5 ... 2.42~rc2-1 (17 versions)2.42-1—

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 42× 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 168 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-27456?
CVE-2026-27456 is a medium vulnerability published on April 3, 2026. util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user…
When was CVE-2026-27456 disclosed?
CVE-2026-27456 was first published in the National Vulnerability Database on April 3, 2026, with the most recent update on July 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27456 actively exploited?
CVE-2026-27456 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 98.1% of all scored CVEs.
What is the CVSS score of CVE-2026-27456?
CVE-2026-27456 has a CVSS v3 base score of 4.7 (NVD).
How do I remediate CVE-2026-27456?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27456, 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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