AIKIDO-2026-212788
cowlib is vulnerable to Improper Output Neutralization
63
Medium Risk
This Affects:
cowlibTL;DR
In cowlib, link Header Directive Smuggling through Unescaped target/rel/Attribute Keys in cow_link:link/1. cow_link:do_link/1 in cowlib interpolates the target URI, rel value, and attribute keys directly into the serialized Link: header value without escaping or token-grammar validation. A > byte in target prematurely closes the URI slot, allowing an attacker to append additional link entries with attacker-chosen rel directives.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range.
Background info
cowlib is vulnerable to Improper Output Neutralization in versions 2.9.0 - 2.19.0.
How to fix this
Upgrade the cowlib library to the patch version.
Links
Fix Commits
github.com/ninenines/cowlib/commit/485d58dfa91b91d98135dc95e5615f421715dae5github.com/ninenines/cowlib/commit/89da27ee4c241f5d649ba7d9b7f2188918af6cea
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SOC 2Compliant
ISO 27001CompliantISO 42001Compliant
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