CVE-2025-66511

Nextcloud Calendar app used predictable proposal participant tokens

CVSS 4.8 MEDIUMEPSS 0.2%CWE-330

Vexday Risk Score

13Baixo

Decisão SSVC (CISA)

Track

Sem sinal de exploração → monitorar

CVSS 4.8EPSS 0.2%KEV nãoPoC —Nuclei —Metasploit —Patch —

Ciclo de vida

05 dez 2025Publicada no NVD

Recomendação: Monitorar — sem sinal de exploração no momento.

Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for meeting proposals using a hash function, allowing an attacker to compute valid participant tokens, which allowed them to request details and submit dates in meeting proposals. The tokens are not purely random generated. This vulnerability is fixed in 6.0.3.

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

Produtos afetados

nextcloud · security-advisories

Quer saber se a sua infraestrutura está exposta a isto?

Falar com a TrueHacking →

Referências

https://github.com/nextcloud/calendar/commit/8de14ae87f321f5f09280d9895a27d54d24f33fb https://github.com/nextcloud/calendar/pull/7659 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-whm3-vv55-gf27 https://hackerone.com/reports/3385434