CVE-2026-77467
7.1HighPublished 15 Oct 2026 · NVD status: Deferred · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Impact
- High impact on availability
- Weakness
- CWE-400, CWE-770
Impact
Authenticated users can cause a denial of service by exhausting web worker CPU or clogging the background image processing queue. An attacker needs an account with upload privileges and a maliciously crafted PDF file.
Root cause
ImagickHandler::loadPdf() lacks pre-render limits on PDF MediaBox dimensions before calling Imagick::readImage().
Affected systems
Lychee prior to 7.7.0
CVSS v4.0 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Fix & remediation
Upgrade to Lychee 7.7.0 or later; if unable to patch immediately, disable PDF uploads or remove Ghostscript PDF handling from ImageMagick's policy.xml.
$ git pull && composer install --no-devAI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
Lychee is a free, open-source photo-management tool. Prior to 7.7.0, Lychee enables ImageMagick PDF support with Ghostscript but does not apply an effective pre-render limit to PDF page dimensions in ImagickHandler::loadPdf(). An authenticated user who can upload a small PDF with an oversized /MediaBox can cause Imagick::readImage() to consume substantial CPU before failing to produce an image. When QUEUE_CONNECTION selects synchronous processing the request can occupy a web worker, while the official asynchronous Docker configuration can clog the shared image-processing queue and delay other work. The advisory did not identify a Ghostscript sandbox escape. This issue is fixed in version 7.7.0.