Uncontrolled resource consumption in Lychee PDF processing
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-400.
Summary
Lychee before 7.7.0 is affected. Lychee enables ImageMagick PDF support with Ghostscript but does not apply an effective limit to PDF page dimensions, which is a missing resource limit (CWE-770). An authenticated user who uploads a small PDF with an oversized MediaBox can make image processing use substantial CPU before it fails, which can occupy a web worker or clog the shared image-processing queue and delay other work.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Lychee 7.7.0 fixes this issue, so update Lychee to version 7.7.0 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Lychee (LycheeOrg) Fixed in 7.7.0
Timeline
- 2026-10-16 Threatist record created from CVE-2026-77467
- 2026-10-16 Priority changed: MEDIUM → LOW
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: LOW → MEDIUM
References
More LycheeOrg vulnerabilities
- TI-2026-74843 Album password bypass in Lychee ZIP downloads CVSS 4.0HIGH 8.2
- TI-2026-74842 Missing rate limiting in Lychee album unlock allows password guessing CVSS 3.1HIGH 7.5
- TI-2024-16953 Cross-site Request Forgery (CSRF) vulnerability in Lychee version 3.1.6, allows remote… CVSS 3.1HIGH 8.3
- TI-2026-74848 Lychee webshop checkout lets buyers override payment amount CVSS 4.0HIGH 8.3
- TI-2026-74845 Payment bypass in Lychee webshop through unrestricted Dummy gateway CVSS 4.0HIGH 8.3
- TI-2024-16952 Cross Site Scripting (XSS) vulnerability in Lychee 3.1.6, allows remote attackers to… CVSS 3.1MEDIUM 6.1
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences