CVE-2026-55497: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the built-in thumbnail and avatar image decoders limit compressed file size but do not limit decoded

mediumCVSS 6.5CVE-2026-55497

Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, the built-in thumbnail and avatar image decoders limit compressed file size but do not limit decoded pixel dimensions, allowing an authenticated user to submit a small PNG, JPEG, or GIF that triggers an unbounded allocation and terminates the Cloudreve process through fatal out-of-memory behavior. This issue is fixed in version 4.17.0.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 6.5
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-2026-55497

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-2026-554970.53% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55497	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

mediumGHSA-g9j2-8w95-3vwv: Cloudreve: Denial of Service - Image decompression / pixel bomb in thumbnail & avatar dec…ghsa

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.

mediumCVE-2026-62323: Cloudreve is a self-hosted file management and sharing system. Prior to 4.17.0, ViewerSessionV…nvd · 2026-07-31
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-2026-55496: 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