CVE-2026-77463 | BDVDB-2026-400556 Detail
umputunremark42
Description#
Remark42 is a self-hosted comment engine for blogs, articles, or any other place where readers can add comments. From 1.0.0 until 1.16.2, Remark42 globally trusts True-Client-IP, X-Real-IP, and X-Forwarded-For without verifying that the direct peer is a trusted proxy, and middleware.RealIP overwrites r.RemoteAddr before per-IP controls run. In a directly reachable deployment, or a proxy that forwards attacker-controlled headers, a remote attacker can rotate spoofed forwarding headers to obtain fresh token buckets for rate-limited endpoints, bypass vote de-duplication when --votes-ip is enabled, mint anonymous identities, and poison stored comment IPs and request logs. The global concurrent-request throttle and per-request timeouts still limit availability impact. Mitigation support is available in version 1.16.2, but operators must configure --trusted-proxy for the deployment topology.
Impact#
Per CVSS v3.1: confidentiality impact none, integrity impact low, availability impact low. Attack vector: network.
Weaknesses#
References#
- https://github.com/umputun/remark42/security/advisories/GHSA-56x6-q882-mf27
- https://github.com/umputun/remark42/pull/2116
- https://github.com/umputun/remark42/pull/2118
- https://github.com/umputun/remark42/commit/b1502801facd7782a1c70fd51f8ad5c2eb650d39
- https://github.com/umputun/remark42/commit/e62b3c830d81659cf5d2687b0c8261da7d42fdab
- https://github.com/umputun/remark42/releases/tag/backend/v1.16.2
- https://remark42.com/docs/configuration/parameters/#trusted-proxies-and-client-ip
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.