SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-77929

ClipBucket v5 before 5.5.3-#182 contains a file upload vulnerability that allows authenticated users to achieve remote code execution by uploading a PHP file with valid image magic bytes through the photo upload endpoint.

HIGH 8.7EPSS 0.94%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.94%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

ClipBucket v5 before 5.5.3-#182 contains a file upload vulnerability that allows authenticated users to achieve remote code execution by uploading a PHP file with valid image magic bytes through the photo upload endpoint. The FileUpload::manageFile() function in fileupload.class.php fails to update the file extension after MIME validation, allowing an attacker-controlled .php extension to persist on disk and execute as PHP via PHP-FPM when the uploaded file is retrieved.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/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
0.94% probability · 61th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-434
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%26 October 2026: 0.94%26 October 202626 October 2026

EPSS 0.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.