CVE Watch22 ago 2026

CVE-2026-75870

Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is declared without a secret.

CVSS

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Sin CVSS

EPSS

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KEV

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Exploit Today

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0-100

Publicado: 22 ago 2026 · Última mod.: 22 ago 2026 · CWE-1394

EPSS · 30d

Sin historial EPSS suficiente todavía.

Descripción técnica

Punk versions before 0.18 for Perl allow session cookie forgery via an empty default HMAC key when a session is declared without a secret. The session keyword freezes its options onto the application as given: it does not require a secret, warn, or refuse to start when one is absent. The cookie read and the write-back both default that key to the empty string, so a declaration with no secret option, or with an undefined or empty one, signs and verifies with a zero-length HMAC-SHA256 key. An attacker who knows the cookie format can then mint one offline carrying any contents the session holds, such as a user identifier or a role. Nothing marks the misconfiguration at runtime: cookies are well formed and sessions round-trip as expected.

Referencias oficiales

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