CVE-2026-9658

High

Description

Plack::Middleware::Security::Common versions before 0.13.1 for Perl did not block header injections in request paths. The header injection rule was ineffective at blocking header injections in the request paths unless they were double-encoded, for example, GET /path\r\nHTTP/1.1\r\nHost: secret.example.com Note that it is unclear whether request paths with CRLF followed by additional headers would be blocked by reverse proxies, or how they would be processed by Plack-based servers.

SeverityHigh

CVSS7.3

Exploit probability—

ProductPlack::Middleware::Security::Common

PublishedMay 28, 2026

First seenMay 28, 2026

Weakness typeCWE-790CWE-790 CWE-113CWE-113

How to fix

Update

RRWO Plack::Middleware::Security::Common0.13.1 or later

Vendor advisories

metacpan.org/release/RRWO/Plack-Middleware-Security-Simple-v0.13.1/changes

Affected products

Product	Affected versions	Fixed in
RRWO Plack::Middleware::Security::Common	v < 0.13.1	0.13.1

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