CVE-2026-55392

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH 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
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.5Exploit: NoneExposed: 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(high)
EPSS
1.3%
KEV
Not listed

Published

June 18, 2026

Last Modified

June 23, 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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 50× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 08:13 UTCEG score recompute
  4. 2026-07-06 08:13 UTCGHSA enrichment
  5. 2026-07-05 05:40 UTCEG score recompute
  6. 2026-07-05 05:40 UTCGHSA enrichment
  7. 2026-07-05 02:31 UTCEPSS rescore
  8. 2026-07-05 02:30 UTCEPSS rescore
  9. 2026-07-04 06:31 UTCEPSS rescore
  10. 2026-07-04 06:31 UTCEPSS rescore
  11. 2026-07-04 03:23 UTCEG score recompute
  12. 2026-07-04 03:23 UTCGHSA enrichment
  13. 2026-07-03 00:32 UTCEG score recompute
  14. 2026-07-03 00:31 UTCGHSA enrichment
  15. 2026-07-01 22:25 UTCEG score recompute
  16. 2026-07-01 22:24 UTCGHSA enrichment
  17. 2026-07-01 15:07 UTCEPSS rescore
  18. 2026-06-30 23:22 UTCEPSS rescore
  19. 2026-06-30 19:50 UTCEG score recompute
  20. 2026-06-30 19:50 UTCGHSA enrichment
  21. 2026-06-29 17:44 UTCEG score recompute
  22. 2026-06-29 17:44 UTCGHSA enrichment
  23. 2026-06-28 15:37 UTCEG score recompute
  24. 2026-06-28 15:37 UTCGHSA enrichment
  25. 2026-06-28 14:07 UTCEPSS rescore
Show 25 more
  1. 2026-06-28 04:56 UTCEPSS rescore
  2. 2026-06-28 04:56 UTCEPSS rescore
  3. 2026-06-27 13:31 UTCEG score recompute
  4. 2026-06-27 13:31 UTCGHSA enrichment
  5. 2026-06-27 03:08 UTCEPSS rescore
  6. 2026-06-26 11:25 UTCEG score recompute
  7. 2026-06-26 11:24 UTCGHSA enrichment
  8. 2026-06-25 13:49 UTCEPSS rescore
  9. 2026-06-25 08:14 UTCEG score recompute
  10. 2026-06-25 08:14 UTCGHSA enrichment
  11. 2026-06-24 14:05 UTCEPSS rescore
  12. 2026-06-24 06:08 UTCEG score recompute
  13. 2026-06-24 06:08 UTCGHSA enrichment
  14. 2026-06-23 21:33 UTCEPSS rescore
  15. 2026-06-23 21:33 UTCEPSS rescore
  16. 2026-06-23 03:58 UTCEG score recompute
  17. 2026-06-23 03:57 UTCGHSA enrichment
  18. 2026-06-22 01:45 UTCEG score recompute
  19. 2026-06-22 01:45 UTCGHSA enrichment
  20. 2026-06-20 23:37 UTCEG score recompute
  21. 2026-06-20 23:37 UTCGHSA enrichment
  22. 2026-06-19 21:31 UTCEG score recompute
  23. 2026-06-19 21:30 UTCGHSA enrichment
  24. 2026-06-18 19:24 UTCEG score recompute
  25. 2026-06-18 19:23 UTCNVD updatefirst tracked

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 June 23, 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 1.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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.

Dependency Blast Radius

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