CVE-2026-40036
Unfurl < 2026.04 - Denial of Service via Unbounded zlib Decompression
HIGH 8.7EPSS 0.8%
Unfurl before 2026.04 contains an unbounded zlib decompression vulnerability in parse_compressed.py that allows remote attackers to cause denial of service. Attackers can submit highly compressed payloads via URL parameters to the /json/visjs endpoint that expand to gigabytes, exhausting server memory and crashing the service.
- Affected
- obsidianforensics · unfurl
- CVSS v4.0 VULNCHECK
- 8.7 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/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 - CVSS v4.0 GitHub
- 8.7 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS v3.1 VULNCHECK
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS
- 0.79% chance of exploitation in the next 30 days, 55th percentile
- Published
- 2026-04-08
- Updated
- 2026-10-08
Proof-of-concept exploits (1)
Security advisories
- obsidianforensics/unfurl/security/advisories/GHSA-h5qv-qjv4-pc5m
- https://www.vulncheck.com/advisories/dfir-unfurl-denial-of-service-via-unbounded-zlib-dec…
- obsidianforensics/unfurl/releases/tag/v2026.04