What is CVE-2026-29086?

CVE-2026-29086 is a medium-severity vulnerability in 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 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: 0.002 (12.1th 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

Hono
Honojs Hono — versions < 4.12.4

Weakness classification (CWE)

CWE-1113

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-29086?: CVE-2026-29086 is a medium-severity vulnerability in 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.