What is CVE-2026-29086?

CVE-2026-29086 is a medium-severity vulnerability in Honojs Hono, classified under CWE-1113. CVSS score: 5.4/10. Published 2026-03-04.

How severe is CVE-2026-29086?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Vulnerability in Honojs Hono

CVE-2026-29086

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to version 4.12.4, the setCookie() utility did not validate semicolons (;), carriage returns (\r), or newline characters (\n) in the domain and pat…

EPSS: 0.000 (12.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.

Affected products

Honojs Hono — versions < 4.12.4

Weakness classification (CWE)

CWE-1113

References

https://github.com/honojs/hono/security/advisories/GHSA-5pq2-9x2x-5p6w (x_refsource_CONFIRM)
https://github.com/honojs/hono/commit/44ae0c8cc4d5ab2bed529127a4ac72e1483ad073 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-29086?: CVE-2026-29086 is a medium-severity vulnerability in Honojs Hono, classified under CWE-1113. CVSS score: 5.4/10. Published 2026-03-04.
How severe is CVE-2026-29086?: Medium severity. CVSS v3 base score is 5.4 out of 10.