CVE-2026-56762

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-06-23. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, 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 before 4.12.12 does not validate cookie names on the write path in the setCookie(), serialize(), and serializeSigned() functions, allowing invalid characters such as control characters (e.g. \r or \n) when an application passes a user-controlled cookie name. This can produce malformed Set-Cookie header values. In modern runtimes such as Node.js and Cloudflare Workers, such invalid header values are rejected and cause a runtime error before the response is sent, so header injection or response splitting could not be reproduced; the issue primarily affects correctness and robustness, resulting in runtime errors (availability) rather than confirmed header injection.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
—
EPSS
16.1%
KEV
Not listed

Published

June 23, 2026

Last Modified

June 24, 2026

Advisory Details (2)

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

Hono - Missing Cookie Name Validation in setCookie() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/hono-missing-cookie-name-validation-in-setcookie
github Patch Available

Missing validation of cookie name on write path in setCookie() · Advisory · honojs/hono · GitHub

https://github.com/honojs/hono/security/advisories/GHSA-26pp-8wgv-hjvm

Vendor Advisories for CVE-2026-56762(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—4.12.12—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 66× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:31 UTCEPSS rescore
  5. 2026-07-19 14:31 UTCEPSS rescore
  6. 2026-07-19 02:29 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-17 06:22 UTCGHSA enrichment
  9. 2026-07-16 17:03 UTCEPSS rescore
  10. 2026-07-16 07:44 UTCGHSA enrichment
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 16:57 UTCEPSS rescore
  13. 2026-07-15 09:06 UTCGHSA enrichment
  14. 2026-07-15 02:00 UTCEPSS rescore
  15. 2026-07-15 02:00 UTCEPSS rescore
  16. 2026-07-14 10:22 UTCGHSA enrichment
  17. 2026-07-13 22:31 UTCEPSS rescore
  18. 2026-07-13 11:44 UTCGHSA enrichment
  19. 2026-07-13 06:13 UTCEPSS rescore
  20. 2026-07-13 06:13 UTCEPSS rescore
  21. 2026-07-12 13:05 UTCGHSA enrichment
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 14:26 UTCGHSA enrichment
  24. 2026-07-11 08:27 UTCEPSS rescore
  25. 2026-07-11 08:27 UTCEPSS rescore
Show 41 more
  1. 2026-07-10 15:49 UTCGHSA enrichment
  2. 2026-07-09 19:10 UTCEPSS rescore
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-09 16:58 UTCGHSA enrichment
  5. 2026-07-08 18:17 UTCGHSA enrichment
  6. 2026-07-08 15:16 UTCEPSS rescore
  7. 2026-07-08 15:16 UTCEPSS rescore
  8. 2026-07-07 19:38 UTCGHSA enrichment
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-06 20:10 UTCGHSA enrichment
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-06 02:23 UTCEPSS rescore
  16. 2026-07-05 21:25 UTCGHSA enrichment
  17. 2026-07-05 02:31 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 22:47 UTCGHSA enrichment
  20. 2026-07-04 00:09 UTCGHSA enrichment
  21. 2026-07-03 01:31 UTCGHSA enrichment
  22. 2026-07-02 02:53 UTCGHSA enrichment
  23. 2026-07-01 15:07 UTCEPSS rescore
  24. 2026-07-01 04:15 UTCGHSA enrichment
  25. 2026-06-30 23:22 UTCEPSS rescore
  26. 2026-06-30 05:36 UTCGHSA enrichment
  27. 2026-06-29 14:06 UTCEPSS rescore
  28. 2026-06-29 06:58 UTCGHSA enrichment
  29. 2026-06-28 14:07 UTCEPSS rescore
  30. 2026-06-28 08:20 UTCGHSA enrichment
  31. 2026-06-28 04:56 UTCEPSS rescore
  32. 2026-06-28 04:56 UTCEPSS rescore
  33. 2026-06-27 09:43 UTCGHSA enrichment
  34. 2026-06-27 03:08 UTCEPSS rescore
  35. 2026-06-26 11:06 UTCGHSA enrichment
  36. 2026-06-25 13:49 UTCEPSS rescore
  37. 2026-06-25 09:58 UTCGHSA enrichment
  38. 2026-06-24 14:05 UTCEPSS rescore
  39. 2026-06-24 11:20 UTCGHSA enrichment
  40. 2026-06-23 12:41 UTCEG score recompute
  41. 2026-06-23 12:40 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56762?
CVE-2026-56762 is a medium vulnerability published on June 23, 2026. Hono before 4.12.12 does not validate cookie names on the write path in the setCookie(), serialize(), and serializeSigned() functions, allowing invalid characters such as control characters (e.g. \r or \n) when an application passes a user-controlled cookie name. This can produce malformed…
When was CVE-2026-56762 disclosed?
CVE-2026-56762 was first published in the National Vulnerability Database on June 23, 2026, with the most recent update on June 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56762 actively exploited?
CVE-2026-56762 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56762?
CVE-2026-56762 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-56762?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56762, 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-2026-56762

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