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
36%
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 / 37× 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 180 total refreshes for this CVE.

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

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 64.3% 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

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