# CVE-2026-54738

## Summary

- **CVE ID:** CVE-2026-54738
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L)
- **CWE:** CWE-799
- **Published:** Aug 19, 2026
- **Last Modified:** Aug 21, 2026

## Description

Lemmy is a link aggregator and forum for the fediverse. Prior to 0.19.19 and 1.0.0-beta.1, actix-web ConnectionInfo::realip_remote_addr reads the first value of X-Forwarded-For as the client address used by raw_ip_key in crates/utils/src/rate_limit/mod.rs. Lemmy's bundled docker/nginx.conf uses $proxy_add_x_forwarded_for instead of $remote_addr, which appends the real client address to an X-Forwarded-For value supplied by the client. An unauthenticated attacker can therefore place a different spoofed address first on each request and receive a new rate-limit bucket, bypassing limits on POST /api/v4/account/auth/register, POST /api/v4/account/auth/login, POST /api/v4/post, POST /api/v4/comment, GET /api/v4/search, POST /api/v4/image, and POST /api/v4/account/import_settings. This permits excessive account creation, brute-force attempts, spam, scraping, uploads, and repeated imports. This issue is fixed in versions 0.19.19 and 1.0.0-beta.1.

## Affected Products

- LemmyNet — lemmy (< 0.19.19)
- LemmyNet — lemmy (>= 1.0.0-alpha.5, < 1.0.0-beta.1)

## References

- [CNA](https://github.com/LemmyNet/lemmy/security/advisories/GHSA-2hrg-7x4g-9vpg)
- [CNA](https://github.com/LemmyNet/lemmy/pull/6574)
- [CNA](https://github.com/LemmyNet/lemmy/pull/6575)
- [CNA](https://github.com/LemmyNet/lemmy/commit/41513c89ceecee719bff05acfe613e3b1e85f23c)
- [CNA](https://github.com/LemmyNet/lemmy/commit/8b5b2aa78417b53ff3622c01f5bed2f1590f3b82)
- [CNA](https://github.com/LemmyNet/lemmy/releases/tag/0.19.19)
- [CNA](https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-beta.1)
- [CNA](https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.43%
- **EPSS Percentile:** 36.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._