CVE-2026-56285

EUVD-2026-40154 · Published Jun 29, 2026

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.

Weaknesses

CWE-1188CWE-918

CVSS scores

v4.07.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/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
v3.18.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

MITRE ATT&CK

Inferred

Where this vulnerability fits in an attack

ReconImpact

Initial Access Persistence Stealth Defense Impairment Credential Access

T1190Exploit Public-Facing Application T1211Exploitation for Stealth T1542.002Component Firmware T1556Modify Authentication Process

References

Potentially impacted assets

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