RCE in Zedeus Nitter
CVE-2026-56285
Nitter's /video media proxy endpoint fails to validate target URLs against Twitter/X domains and uses a hardcoded default HMAC key, allowing unauthenticated attackers to compute valid HMACs for arbitrary URLs. Attackers can retrieve HTTP responses from any host reachable by the server, including cloud metadata services and internal network resources.
Vulnerability class: SSRF (Server-Side Request Forgery)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (39.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- Zedeus Nitter — versions 0
Weakness classification (CWE)
References
- github.com/zedeus/nitter/commit/44b2f096f67da2cc257a0e262a94a7ae79e95d47 (patch)
- github.com/zedeus/nitter/issues/1411 (issue-tracking)
- www.vulncheck.com/advisories/nitter-server-side-request-forgery-in-video-media-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56285?
- CVE-2026-56285 is a high-severity vulnerability in Zedeus Nitter, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.6/10. Published 2026-06-29.
- How severe is CVE-2026-56285?
- High severity. CVSS v3 base score is 8.6 out of 10.