Is CVE-2026-27700 actively exploited?

No active exploitation of CVE-2026-27700 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-27700 be exploited remotely?

Yes. CVE-2026-27700 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-27700?

CVE-2026-27700 has a CVSS score of 7.5 (HIGH) and an EPSS exploitation probability of 0.01%.

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HIGH

CVE-2026-27700

CWE-290Published: February 25, 2026· Updated: Mar 2, 2026

7.5

CVSS v3.1

EPSS:0.01%probability of exploitation in 30 daysPercentile:2.7th

Official Description

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()` function incorrectly selected the first value from the `X-Forwarded-For` header. Because AWS ALB appends the real client IP address to the end of the `X-Forwarded-For` header, the first value can be attacker-controlled. This could allow IP-based access control mechanisms (such as the `ipRestriction` middleware) to be bypassed. Version 4.12.2 patches the issue.

NVD Source

Technical Analysis

CVE-2026-27700 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 7.5.