CVE-2026-29086

low-risk
Published 2026-03-04

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 path options when constructing the Set-Cookie header. Because cookie attributes are delimited by semicolons, this could allow injection of additional cookie attributes if untrusted input was passed into these fields. This issue has been patched in version 4.12.4.

Do I need to act?

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0.03% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.4/10 Medium
NETWORK / LOW complexity

Affected Products (1)

Hono

Affected Vendors

26
/ 100
low-risk
Severity 21/34 · High
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal