CVE-2026-56762

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM 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
Trending — 3 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 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(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
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 12× 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. 2026-07-26 15:55 UTCEG score recompute
  2. 2026-07-26 15:54 UTCGHSA enrichment
  3. 2026-07-26 14:54 UTCEPSS rescore
  4. 2026-07-26 14:54 UTCEPSS rescore
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-25 14:18 UTCEPSS rescore
  7. 2026-07-24 14:18 UTCEPSS rescore
  8. 2026-07-23 14:18 UTCEPSS rescore
  9. 2026-07-23 03:20 UTCEG score recompute
  10. 2026-07-22 14:08 UTCEPSS rescore
  11. 2026-07-21 15:25 UTCEPSS rescore
  12. 2026-07-20 17:08 UTCEPSS rescore
  13. 2026-07-19 14:31 UTCEPSS rescore
  14. 2026-07-19 14:31 UTCEPSS rescore
  15. 2026-07-19 02:29 UTCEPSS rescore
  16. 2026-07-18 10:04 UTCEPSS rescore
  17. 2026-07-17 06:22 UTCGHSA enrichment
  18. 2026-07-16 17:03 UTCEPSS rescore
  19. 2026-07-16 07:44 UTCGHSA enrichment
  20. 2026-07-15 16:57 UTCEPSS rescore
  21. 2026-07-15 16:57 UTCEPSS rescore
  22. 2026-07-15 09:06 UTCGHSA enrichment
  23. 2026-07-15 02:00 UTCEPSS rescore
  24. 2026-07-15 02:00 UTCEPSS rescore
  25. 2026-07-14 10:22 UTCGHSA enrichment
Show 50 more
  1. 2026-07-13 22:31 UTCEPSS rescore
  2. 2026-07-13 11:44 UTCGHSA enrichment
  3. 2026-07-13 06:13 UTCEPSS rescore
  4. 2026-07-13 06:13 UTCEPSS rescore
  5. 2026-07-12 13:05 UTCGHSA enrichment
  6. 2026-07-12 05:46 UTCEPSS rescore
  7. 2026-07-11 14:26 UTCGHSA enrichment
  8. 2026-07-11 08:27 UTCEPSS rescore
  9. 2026-07-11 08:27 UTCEPSS rescore
  10. 2026-07-10 15:49 UTCGHSA enrichment
  11. 2026-07-09 19:10 UTCEPSS rescore
  12. 2026-07-09 19:10 UTCEPSS rescore
  13. 2026-07-09 16:58 UTCGHSA enrichment
  14. 2026-07-08 18:17 UTCGHSA enrichment
  15. 2026-07-08 15:16 UTCEPSS rescore
  16. 2026-07-08 15:16 UTCEPSS rescore
  17. 2026-07-07 19:38 UTCGHSA enrichment
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-06 20:10 UTCGHSA enrichment
  21. 2026-07-06 16:27 UTCEPSS rescore
  22. 2026-07-06 16:27 UTCEPSS rescore
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-06 02:23 UTCEPSS rescore
  25. 2026-07-05 21:25 UTCGHSA enrichment
  26. 2026-07-05 02:31 UTCEPSS rescore
  27. 2026-07-05 02:30 UTCEPSS rescore
  28. 2026-07-04 22:47 UTCGHSA enrichment
  29. 2026-07-04 00:09 UTCGHSA enrichment
  30. 2026-07-03 01:31 UTCGHSA enrichment
  31. 2026-07-02 02:53 UTCGHSA enrichment
  32. 2026-07-01 15:07 UTCEPSS rescore
  33. 2026-07-01 04:15 UTCGHSA enrichment
  34. 2026-06-30 23:22 UTCEPSS rescore
  35. 2026-06-30 05:36 UTCGHSA enrichment
  36. 2026-06-29 14:06 UTCEPSS rescore
  37. 2026-06-29 06:58 UTCGHSA enrichment
  38. 2026-06-28 14:07 UTCEPSS rescore
  39. 2026-06-28 08:20 UTCGHSA enrichment
  40. 2026-06-28 04:56 UTCEPSS rescore
  41. 2026-06-28 04:56 UTCEPSS rescore
  42. 2026-06-27 09:43 UTCGHSA enrichment
  43. 2026-06-27 03:08 UTCEPSS rescore
  44. 2026-06-26 11:06 UTCGHSA enrichment
  45. 2026-06-25 13:49 UTCEPSS rescore
  46. 2026-06-25 09:58 UTCGHSA enrichment
  47. 2026-06-24 14:05 UTCEPSS rescore
  48. 2026-06-24 11:20 UTCGHSA enrichment
  49. 2026-06-23 12:41 UTCEG score recompute
  50. 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 0% probability of exploitation in the next 30 days, which ranks it in the top 83.9% of all scored CVEs.
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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