{"id":"CVE-2026-42181","summary":"Lemmy: SSRF and internal image disclosure in post link metadata via unvalidated og:image","details":"Lemmy is a link aggregator and forum for the fediverse. Prior to version 0.19.18, Lemmy fetches metadata for user-supplied post URLs and, under the default StoreLinkPreviews image mode, downloads the preview image through local pict-rs. While the top-level page URL is checked against internal IP ranges, the extracted og:image URL is not subject to the same restriction. As a result, an authenticated low-privileged user can submit an attacker-controlled public page whose Open Graph image points to an internal image endpoint. Lemmy will fetch that internal image server-side and store a local thumbnail that can then be served back to users. This issue has been patched in version 0.19.18.","aliases":["GHSA-h6hf-9846-xwrq"],"modified":"2026-07-15T01:48:56.526560302Z","published":"2026-05-08T19:26:07.763Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42181.json"},"references":[{"type":"WEB","url":"https://github.com/LemmyNet/lemmy/releases/tag/0.19.18"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42181.json"},{"type":"ADVISORY","url":"https://github.com/LemmyNet/lemmy/security/advisories/GHSA-h6hf-9846-xwrq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42181"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/lemmynet/lemmy","events":[{"introduced":"0"},{"fixed":"f32dd84d04541f8a94fee29d1f47f3f8eeaec0be"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"0.19.18"}]}}],"versions":["0.19.18-beta.3","0.19.18-beta.1","0.19.18-beta.0","0.19.17","0.19.17-beta.0","0.19.16","0.19.16-beta.1","0.19.16-beta.0","0.19.15","0.19.15-beta.0","0.19.14","0.19.14-beta.2","0.19.14-beta.1","0.19.14-beta.0","0.19.13","0.19.13-beta.1","0.19.12","0.19.12-beta.12","0.19.12-beta.11","0.19.12-beta.10","0.19.12-beta.9","0.19.12-beta.8","0.19.12-beta.7","0.19.12-beta.6","0.19.12-beta.5","0.19.12-beta.4","0.19.12-beta.3","0.19.12-beta.2","0.19.12-beta.1","0.19.12-beta.0","0.19.11","0.19.11-beta.2","0.19.11-beta.1","0.19.11-beta.0","0.19.10","0.19.10-beta.2","0.19.10-beta.1","0.19.10-beta.0","0.19.9","0.19.9-beta.4","0.19.9-beta.3","0.19.9-beta.2","0.19.9-beta.1","0.19.9-beta.0","0.19.8","0.19.8-beta.0","0.19.7","0.19.7-beta.2","0.19.7-beta.1","0.19.6","0.19.6-beta.15","0.19.6-beta.14","0.19.6-beta.9","0.19.6-beta.8","0.19.5","0.19.5-alpha.3","0.19.5-alpha.2","0.19.5-alpha.1","0.19.4","0.19.4-rc.11","0.19.4-rc.10","0.19.4-rc.9","0.19.4-rc.8","0.19.4-rc.7","0.19.4-rc.6","0.19.4-rc.5","0.19.4-rc.4","0.19.4-rc.3","0.19.4-rc.2","0.19.4-rc.1","0.19.4-beta.8","0.19.4-beta.7","0.19.4-beta.6","0.19.4-beta.5","0.19.4-beta.4","0.19.4-beta.3","0.19.4-beta.1","0.19.3","0.19.3-rc.1","0.19.2","0.19.2-rc.5","0.19.2-rc.4","0.19.2-rc.2","0.19.2-rc.1","0.19.1-rc.2","0.19.1-rc.1","0.19.0","0.19.0-rc.16","0.19.0-rc.15","0.19.0-rc.14","0.19.0-rc.13","0.19.0-rc.12","0.19.0-rc.11","0.19.0-rc.10","0.19.0-rc.8","0.19.0-rc.7","0.19.0-rc.6","0.19.0-rc.5","0.19.0-rc.4","0.19.0-rc.3","0.19.0-rc.2","0.19.0-beta.7","0.19.0-rc.1","0.18.4-beta.7","0.18.1","0.18.1-rc.10","0.18.1-rc.9","0.18.1-rc.4","0.18.1-rc.1","0.18.0","0.18.0-rc.8","0.18.0-rc.6","0.18.0-rc.5","0.18.0-rc.4","0.18.0-rc.3","0.18.0-rc.2","0.18.0-rc.1","0.17.1","0.17.0","0.17.0-rc.4","0.17.0-rc.3","0.17.0-rc.1","0.16.5","0.16.3","0.16.3-rc.1","0.16.2","0.16.2-rc.3","0.16.2-rc.2","0.16.2-rc.1","0.16.1","0.16.1-rc.1","0.16.0","0.16.0-rc.4","0.16.0-rc.3","0.16.0-rc.2","0.16.0-rc.1","0.15.1","0.15.0","0.15.0-rc.7","0.14.3","0.14.2","0.14.2-rc.1","0.14.1","0.14.0","0.14.0-rc.2","0.14.0-rc.1","0.13.6-rc.2","0.13.5-rc.7","0.13.0","0.13.0-rc.1","0.12.0","0.12.0-rc.2","0.12.0-rc.1","0.11.4-rc.16","0.11.3-rc.4","0.11.0","0.11.2","0.11.1","0.11.0-rc.1","0.10.2","0.10.1","0.10.0","0.10.0-rc.13","0.10.0-rc.12","0.10.0-rc.7","0.9.9","0.9.8","0.9.7","0.9.6","0.9.5","0.9.4","0.9.3","0.9.2","0.9.1","0.9.0","v0.8.10","v0.8.9","v0.8.8","v0.8.7","v0.8.6","v0.8.5","v0.8.3","v0.8.1","v0.8.0","v0.7.64","v0.7.63","v0.7.62","v0.7.61","v0.7.59","v0.7.57","v0.7.56","v0.7.55","v0.7.54","v0.7.53","v0.7.52","v0.7.50","v0.7.49","v0.7.48","v0.7.43","v0.7.47","v0.7.46","v0.7.44","v0.7.42","v0.7.41","v0.7.40","v0.7.39","v0.7.38","v0.7.37","v0.7.36","v0.7.35","v0.7.34","v0.7.31","v0.7.33","v0.7.32","v0.7.26","v0.7.30","v0.7.29","v0.7.28","v0.7.25","v0.7.24","v0.7.23","v0.7.22","v0.7.21","v0.7.19","v0.7.20","v0.7.18","v0.7.17","v0.7.8","v0.7.7","v0.7.6","v0.7.5","v0.7.4","v0.7.3","v0.5.10","v0.4.0.3","v0.0.8.3","v0.0.8.2","v0.0.8.1","v0.0.7.4"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42181.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"}]}