CVE-2026-56285

high

Published 2026-06-29 · Modified 2026-06-29

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CVSS v3

8.6

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS v4 NEW

7.7

CVSS: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

VIR risk

8.6

Description

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.

Predictions

Exploit likelihood

91%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-918 CWE-1188

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.