CVE-2026-55392

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2026-06-18. a secondary CVSS source baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
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: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

NILFS utilities through 2.3.0, fixed in commit 26efb5d, nilfs_sb_is_valid() function fails to validate s_log_block_size field in NILFS2 superblock before bit-shift operations. Attackers supplying crafted NILFS2 images trigger undefined behavior through oversized shifts or out-of-memory conditions, crashing tools like nilfs-tune and dumpseg.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
25(Track)
EG Risk 25/100SSVC: 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%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
4%
KEV
Not listed

Published

June 18, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Jun 18, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

Security: Missing s_log_block_size validation causes UB shift and OOM DoS · Issue #26 · nilfs-dev/nilfs-utils · GitHub

https://github.com/nilfs-dev/nilfs-utils/issues/26
github_commit

commit 26efb5daff07 (nilfs-dev/nilfs-utils)

Fix landed in nilfs-dev/nilfs-utils commit 26efb5daff07 — awaiting tagged release

https://github.com/nilfs-dev/nilfs-utils/commit/26efb5daff0757365101035145331b0a5a85d9d9

Vendor Advisories for CVE-2026-55392(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
nilfs-tools2.2.11-1, 2.2.11-2, 2.2.8-1, 2.2.9-1——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
nilfs-tools2.2.11-1, 2.2.11-2, 2.2.9-1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
nilfs-tools2.2.11-2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
nilfs-tools2.2.11-2——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 71× 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 136 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-55392?
CVE-2026-55392 is a medium vulnerability published on June 18, 2026. NILFS utilities through 2.3.0, fixed in commit 26efb5d, nilfssbisvalid() function fails to validate slogblocksize field in NILFS2 superblock before bit-shift operations. Attackers supplying crafted NILFS2 images trigger undefined behavior through oversized shifts or out-of-memory conditions,…
When was CVE-2026-55392 disclosed?
CVE-2026-55392 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55392 actively exploited?
CVE-2026-55392 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 95.5% of all scored CVEs.
What is the CVSS score of CVE-2026-55392?
CVE-2026-55392 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2026-55392?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55392, 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.

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