https://vulnerability.circl.lu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Mon, 28 Sep 2026 20:24:54 +0000 https://vulnerability.circl.lu/vuln/cve-2026-43971 <p><strong>Affected:</strong> ninenines cowlib</p> <p>Improper Encoding or Escaping of Output vulnerability in ninenines cowlib allows Link header directive smuggling via unescaped special characters in cow_link:link/1.</p> <p>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 &gt; byte in target prematurely closes the URI slot, allowing an attacker to append additional link entries with attacker-chosen rel directives. A &#34; or \ in rel escapes the quoted string and opens new parameters. Any byte — including whitespace, =, and &#34; — in an attribute key is emitted verbatim. Because browsers act on Link: directives such as rel=&#34;preconnect&#34;, rel=&#34;preload&#34;, and rel=&#34;prerender&#34;, an attacker who can influence these fields in an application that round-trips parsed Link headers through cow_link:link/1 can force victim browsers to make out-of-band connections to attacker-controlled origins.</p> <p>This issue affects cowlib: from 2.9.0 before 2.20.0.</p> <p><strong>Affected:</strong> ninenines cowlib</p> <p>Improper Encoding or Escaping of Output vulnerability in ninenines cowlib allows Link header directive smuggling via unescaped special characters in cow_link:link/1.</p> <p>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 &gt; byte in target prematurely closes the URI slot, allowing an attacker to append additional link entries with attacker-chosen rel directives. A &#34; or \ in rel escapes the quoted string and opens new parameters. Any byte — including whitespace, =, and &#34; — in an attribute key is emitted verbatim. Because browsers act on Link: directives such as rel=&#34;preconnect&#34;, rel=&#34;preload&#34;, and rel=&#34;prerender&#34;, an attacker who can influence these fields in an application that round-trips parsed Link headers through cow_link:link/1 can force victim browsers to make out-of-band connections to attacker-controlled origins.</p> <p>This issue affects cowlib: from 2.9.0 before 2.20.0.</p> https://vulnerability.circl.lu/vuln/cve-2026-43971