{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-54738", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-15T23:07:33.233Z", "datePublished": "2026-08-19T20:27:45.162Z", "dateUpdated": "2026-08-19T20:27:45.162Z"}, "containers": {"cna": {"title": "Lemmy: Rate limit bypass via X-Forwarded-For header spoofing in actix-web ConnectionInfo", "problemTypes": [{"descriptions": [{"cweId": "CWE-799", "lang": "en", "description": "CWE-799: Improper Control of Interaction Frequency", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L", "version": "3.1"}}], "references": [{"name": "https://github.com/LemmyNet/lemmy/security/advisories/GHSA-2hrg-7x4g-9vpg", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/LemmyNet/lemmy/security/advisories/GHSA-2hrg-7x4g-9vpg"}, {"name": "https://github.com/LemmyNet/lemmy/pull/6574", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/pull/6574"}, {"name": "https://github.com/LemmyNet/lemmy/pull/6575", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/pull/6575"}, {"name": "https://github.com/LemmyNet/lemmy/commit/41513c89ceecee719bff05acfe613e3b1e85f23c", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/commit/41513c89ceecee719bff05acfe613e3b1e85f23c"}, {"name": "https://github.com/LemmyNet/lemmy/commit/8b5b2aa78417b53ff3622c01f5bed2f1590f3b82", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/commit/8b5b2aa78417b53ff3622c01f5bed2f1590f3b82"}, {"name": "https://github.com/LemmyNet/lemmy/releases/tag/0.19.19", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/releases/tag/0.19.19"}, {"name": "https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-beta.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-beta.1"}, {"name": "https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19", "tags": ["x_refsource_MISC"], "url": "https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19"}], "affected": [{"vendor": "LemmyNet", "product": "lemmy", "versions": [{"version": "< 0.19.19", "status": "affected"}, {"version": ">= 1.0.0-alpha.5, < 1.0.0-beta.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-19T20:27:45.162Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-2hrg-7x4g-9vpg", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "lemmy", "vendor": "LemmyNet", "versions": [{"status": "affected", "version": "< 0.19.19"}, {"status": "affected", "version": ">= 1.0.0-alpha.5, < 1.0.0-beta.1"}]}], "source": "[email protected]"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-54738", "lastModified": "2026-08-19T21:16:58.073", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 6.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 2.5, "source": "[email protected]", "type": "Secondary"}]}, "published": "2026-08-19T21:16:58.073", "references": [{"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/commit/41513c89ceecee719bff05acfe613e3b1e85f23c"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/commit/8b5b2aa78417b53ff3622c01f5bed2f1590f3b82"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/pull/6574"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/pull/6575"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/releases/tag/0.19.19"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/releases/tag/1.0.0-beta.1"}, {"source": "[email protected]", "url": "https://github.com/LemmyNet/lemmy/security/advisories/GHSA-2hrg-7x4g-9vpg"}, {"source": "[email protected]", "url": "https://join-lemmy.org/news/2026-06-09_-_Lemmy_Release_v0.19.19"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-799"}], "source": "[email protected]", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.19.19)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.0.0-alpha.5,1.0.0-beta.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "lemmy", "source": "cna", "vendor": "LemmyNet"}, "product": "lemmy", "vendor": "lemmynet"}], "created": "2026-08-19T21:45:07.366825+00:00", "updated": "2026-08-19T22:15:04.193254+00:00", "vendors": ["lemmynet", "lemmynet$PRODUCT$lemmy"]}