CVE-2026-62323: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionValidation uses only the session-id prefix of a WOPI access token and does not enforce

mediumCVSS 6.3CVE-2026-62323

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionValidation uses only the session-id prefix of a WOPI access token and does not enforce the requested viewer action, allowing a malicious or compromised WOPI viewer with a view session to forge the token suffix and invoke WOPI write routes for the underlying file. This issue is fixed in version 4.17.0.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 6.3
Published: 2026-07-31
Last updated: 2026-07-31
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-62323

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-623230.31% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 23% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-62323	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

mediumGHSA-c3jm-gv5r-9wcp: Cloudreve WOPI view sessions can write files and WOPI access token secret is ignoredghsa

Recent advisories for Cloudreve is a

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-55502: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, POST /api/v4/a…nvd · 2026-07-31
mediumCVE-2026-55499: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, a single-file …nvd · 2026-07-31
mediumCVE-2026-55497: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the built-in t…nvd · 2026-07-31
mediumCVE-2026-55496: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, GET /api/v4/us…nvd · 2026-07-31
mediumCVE-2026-55495: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the WOPI PUT_R…nvd · 2026-07-31
mediumGHSA-v6w6-358x-2433: Cloudreve Admin.Read OAuth tokens can trigger server-side node test requestsghsa · 2026-07-24