CVE-2026-54287

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% 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, secondary
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

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

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda, the ALB single-header response and the VPC Lattice v2 response join multiple Set-Cookie headers into one comma-separated value. Because commas also appear inside cookie attributes (for example Expires dates), clients cannot split the value back into individual cookies and silently drop or misparse them. This vulnerability is fixed in 4.12.25.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
8.3%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 22, 2026

Advisory Details (1)

Auto-updated Jun 23, 2026
Patch available. Sources: github.
github Patch Available

AWS Lambda adapter merges multiple `Set-Cookie` headers into one value, dropping cookies on ALB single-header and Lattice · Advisory · honojs/hono · GitHub

https://github.com/honojs/hono/security/advisories/GHSA-j6c9-x7qj-28xf

Vendor Advisories for CVE-2026-54287(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
hono—4.12.25—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 40× 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 23:15 UTCEG score recompute
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-05 10:57 UTCEG score recompute
  5. 2026-07-05 02:31 UTCEPSS rescore
  6. 2026-07-05 02:30 UTCEPSS rescore
  7. 2026-07-04 12:25 UTCEG score recompute
  8. 2026-07-04 06:31 UTCEPSS rescore
  9. 2026-07-04 06:31 UTCEPSS rescore
  10. 2026-07-03 13:49 UTCEG score recompute
  11. 2026-07-02 14:32 UTCEG score recompute
  12. 2026-07-01 16:00 UTCEG score recompute
  13. 2026-07-01 15:07 UTCEPSS rescore
  14. 2026-06-30 23:22 UTCEPSS rescore
  15. 2026-06-30 17:27 UTCEG score recompute
  16. 2026-06-29 18:38 UTCEG score recompute
  17. 2026-06-29 14:06 UTCEPSS rescore
  18. 2026-06-29 14:06 UTCEPSS rescore
  19. 2026-06-28 20:06 UTCEG score recompute
  20. 2026-06-28 14:07 UTCEPSS rescore
  21. 2026-06-28 04:56 UTCEPSS rescore
  22. 2026-06-28 04:56 UTCEPSS rescore
  23. 2026-06-27 21:34 UTCEG score recompute
  24. 2026-06-27 03:08 UTCEPSS rescore
  25. 2026-06-26 23:01 UTCEG score recompute
Show 15 more
  1. 2026-06-26 00:28 UTCEG score recompute
  2. 2026-06-25 13:49 UTCEPSS rescore
  3. 2026-06-25 01:55 UTCEG score recompute
  4. 2026-06-24 14:05 UTCEPSS rescore
  5. 2026-06-24 03:23 UTCEG score recompute
  6. 2026-06-23 21:33 UTCEPSS rescore
  7. 2026-06-23 21:33 UTCEPSS rescore
  8. 2026-06-23 04:50 UTCEG score recompute
  9. 2026-06-22 06:13 UTCEG score recompute
  10. 2026-06-21 07:25 UTCEG score recompute
  11. 2026-06-20 08:23 UTCEG score recompute
  12. 2026-06-19 09:50 UTCEG score recompute
  13. 2026-06-18 11:16 UTCEG score recompute
  14. 2026-06-17 12:41 UTCEG score recompute
  15. 2026-06-16 14:09 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-54287?
CVE-2026-54287 is a medium vulnerability published on June 16, 2026. Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda, the ALB single-header response and the VPC Lattice v2 response join multiple Set-Cookie headers into one comma-separated value. Because commas also appear inside cookie attributes…
When was CVE-2026-54287 disclosed?
CVE-2026-54287 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54287 actively exploited?
CVE-2026-54287 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54287?
CVE-2026-54287 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-54287?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54287, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54287

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