CVE-2026-42451

Grimmory: Stored XSS via Malicious EPUB Enables Session Token Theft

CVSS 6.3 MEDIUMEPSS 0.1%CWE-79 CWE-80

Vexday Risk Score

13Baixo

Decisão SSVC (CISA)

Track

Sem sinal de exploração → monitorar

CVSS 6.3EPSS 0.1%KEV nãoPoC —Nuclei —Metasploit —Patch —

Ciclo de vida

08 mai 2026Publicada no NVD

Recomendação: Monitorar — sem sinal de exploração no momento.

Grimmory is a self-hosted digital library. Prior to version 2.3.1, a stored cross-site scripting (XSS) vulnerability in Grimmory's browser-based EPUB reader allows an attacker to embed arbitrary JavaScript in a crafted EPUB file. When a victim opens the book, the script executes in their browser with full access to the Grimmory application's session context. This can enable session token theft and account takeover, including administrative access if an administrator opens the affected book. This issue has been patched in version 2.3.1.

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:L

Produtos afetados

grimmory-tools · grimmory

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Referências

http://github.com/grimmory-tools/grimmory/releases/tag/v2.3.1 https://github.com/grimmory-tools/grimmory/security/advisories/GHSA-frv6-5wq5-9p24