What is CVE-2026-27700?

CVE-2026-27700 is a high-severity vulnerability in Hono, classified under Authentication Bypass by Spoofing. CVSS score: 8.2/10. Published 2026-02-25.

How severe is CVE-2026-27700?

High severity. CVSS v3 base score is 8.2 out of 10.

Vulnerability in Hono

CVE-2026-27700

Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (`hono/aws-lambda`) behind an Application Load Balancer (ALB), the `getConnInfo()` funct…

EPSS: 0.002 (15.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

Affected products

Hono
Honojs Hono — versions >= 4.12.0, < 4.12.2

Weakness classification (CWE)

References

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

Frequently asked questions

What is CVE-2026-27700?: CVE-2026-27700 is a high-severity vulnerability in Hono, classified under Authentication Bypass by Spoofing. CVSS score: 8.2/10. Published 2026-02-25.
How severe is CVE-2026-27700?: High severity. CVSS v3 base score is 8.2 out of 10.