{"id":"CVE-2026-42181","revision":"cf0f62042a6c483f933b857b4e7c08fb","records":[{"revision":"cf0f62042a6c483f933b857b4e7c08fb","observedAt":"2026-10-25T10:17:10.603+00:00","statement":{"source":"nvd","id":"CVE-2026-42181","aliases":[],"title":"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. Whi…","description":"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.","state":0,"publishedAt":"2026-05-08T20:16:31.16+00:00","modifiedAt":"2026-06-17T10:47:28.533+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","score":6.5,"severity":"MEDIUM"}],"references":["https://github.com/LemmyNet/lemmy/releases/tag/0.19.18","https://github.com/LemmyNet/lemmy/security/advisories/GHSA-h6hf-9846-xwrq"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-42181","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-918"],"productCriteria":[],"sourceDates":{"published":"2026-05-08T20:16:31.160","lastModified":"2026-06-17T10:47:28.533"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-42181","identifiers":["CVE-2026-42181"]},"retained":false,"historicalAffected":[]}],"coverage":[]}