CVE-2026-56761

Description

hono before 4.12.14 contains an html injection vulnerability in jsx server-side rendering that allows attackers to inject unintended html by using malformed attribute names. Attackers can craft specially crafted attribute keys containing characters like quotes or angle brackets to break html tag boundaries and inject arbitrary attributes or elements.

CVSS v3.1 Score

4.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
hono	hono	< 4.12.14

References

Advisories & Patches

https://github.com/honojs/hono/security/advisories/GHSA-458j-xx4x-4375

Other References

https://www.vulncheck.com/advisories/hono-html-injection-via-improper-jsx-attribute-name-handling-in-ssr

Frequently Asked Questions

What is CVE-2026-56761? +

hono before 4.12.14 contains an html injection vulnerability in jsx server-side rendering that allows attackers to inject unintended html by using malformed attribute names. Attackers can craft specially crafted attribute keys containing characters like quotes or angle brackets to break html tag boundaries and inject arbitrary attributes or elements. It has a CVSS v3.1 base score of 4.3 (MEDIUM).

How severe is CVE-2026-56761? +

CVE-2026-56761 has a CVSS v3.1 score of 4.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0017, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-56761? +

CVE-2026-56761 affects products from hono, specifically: hono. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-56761? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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