CVE-2026-54738
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 read
CVSS
6.5
Medium
EPSS
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KEV
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Exploit Today
0
0-100
Published: Aug 19, 2026 · Last modified: Aug 19, 2026 · CWE-799
Not enough EPSS history yet.
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.
- github.comhttps://github.com/LemmyNet/lemmy/commit/41513c89ceecee719bff05acfe613e3b1e85f23c
- github.comhttps://github.com/LemmyNet/lemmy/commit/8b5b2aa78417b53ff3622c01f5bed2f1590f3b82
- github.comhttps://github.com/LemmyNet/lemmy/pull/6574
- github.comhttps://github.com/LemmyNet/lemmy/pull/6575
- github.comhttps://github.com/LemmyNet/lemmy/releases/tag/0.19.19
- github.comhttps://github.com/LemmyNet/lemmy/releases/tag/1.0.0-beta.1
- github.comhttps://github.com/LemmyNet/lemmy/security/advisories/GHSA-2hrg-7x4g-9vpg
- join-lemmy.orghttps://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19