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
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.5Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

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
5.5MEDIUMmedium confidence
EG Risk
25
EG Risk 25/100

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%
EPSS PROB
0.2%
EPSS %ILE
3rd
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 rangeFix by version rangeDependents
nilfs-tools2.2.11-1, 2.2.11-2, 2.2.8-1, 2.2.9-1
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nilfs-tools2.2.11-1, 2.2.11-2, 2.2.9-1
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nilfs-tools2.2.11-2
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nilfs-tools2.2.11-2
  • every version on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 27× 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 178 total refreshes for this CVE.

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

Related CVEs(same CWE)

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 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 0.2% probability of exploitation in the next 30 days (3rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55392?
CVE-2026-55392 has a CVSS base score of 5.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55392?
An upstream fix for CVE-2026-55392 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-55392 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55392

Explore →

Is Your Infrastructure Affected by CVE-2026-55392?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs