---
id: CVE-2026-77463
title: >-
  Remark42: Rate limit bypass via unconditional trust of
  X-Forwarded-For/X-Real-IP headers in direct-internet deployment
summary: >-
  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 …
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'
cvssSource: cna
cwe:
  - CWE-348
  - CWE-807
vendor: umputun
product: remark42
affected:
  - 'remark42 >= 1.0.0, < 1.16.2'
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:54:09.798Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-77463'
references:
  - url: >-
      https://github.com/umputun/remark42/security/advisories/GHSA-56x6-q882-mf27
    label: >-
      https://github.com/umputun/remark42/security/advisories/GHSA-56x6-q882-mf27
  - url: 'https://github.com/umputun/remark42/pull/2116'
    label: 'https://github.com/umputun/remark42/pull/2116'
  - url: 'https://github.com/umputun/remark42/pull/2118'
    label: 'https://github.com/umputun/remark42/pull/2118'
  - url: >-
      https://github.com/umputun/remark42/commit/b1502801facd7782a1c70fd51f8ad5c2eb650d39
    label: >-
      https://github.com/umputun/remark42/commit/b1502801facd7782a1c70fd51f8ad5c2eb650d39
  - url: >-
      https://github.com/umputun/remark42/commit/e62b3c830d81659cf5d2687b0c8261da7d42fdab
    label: >-
      https://github.com/umputun/remark42/commit/e62b3c830d81659cf5d2687b0c8261da7d42fdab
  - url: 'https://github.com/umputun/remark42/releases/tag/backend/v1.16.2'
    label: 'https://github.com/umputun/remark42/releases/tag/backend/v1.16.2'
  - url: >-
      https://remark42.com/docs/configuration/parameters/#trusted-proxies-and-client-ip
    label: >-
      https://remark42.com/docs/configuration/parameters/#trusted-proxies-and-client-ip
tags:
  - cve.org
ingestedAt: '2026-11-05T22:38:31.937Z'
epss: 0.00219
epssPercentile: 0.12452
---

## Overview

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.

## Affected

- `remark42 >= 1.0.0, < 1.16.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.