CVE-2026-25728
Prior to 5.5.3 - #40, a Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability exists in ClipBucket's avatar and background image upload functionality.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
ClipBucket v5 is an open source video sharing platform. Prior to 5.5.3 - #40, a Time-of-Check to Time-of-Use (TOCTOU) race condition vulnerability exists in ClipBucket's avatar and background image upload functionality. The application moves uploaded files to a web-accessible location before validating them, creating a window where an attacker can execute arbitrary PHP code before the file is deleted. The uploaded file was moved to a web-accessible path via move_uploaded_file(), then validated via ValidateImage(). If validation failed, the file was deleted via @unlink(). This vulnerability is fixed in 5.5.3 - #40.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.29% probability · 22th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- oxygenz/clipbucket
- Source
- security-advisories@github.com
References
- https://github.com/MacWarrior/clipbucket-v5/commit/09536e6e2ca6d69a2ee83190b588c0b8116dd16dPatch
- https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-xq7c-m5r2-9wqjExploit, Mitigation, Vendor Advisory
- https://github.com/MacWarrior/clipbucket-v5/security/advisories/GHSA-xq7c-m5r2-9wqjExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.