CVE-2026-111720

fish-island-backend through commit 7c61b78 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server fetch attacker-supplied URLs via the url parameter of GET /api/web/parse. Attackers can target internal hosts, loopback services or cloud metadata endpoints through redirect-following OkHttp requests and read back page titles, meta descriptions and favicons.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

• https://github.com/lhccong/fish-island-backend/blob/7c61b7861e99d3970beb34103c244b79e4de7d88/src/main/java/com/cong/fishisland/config/CorsConfig.java#L33
• https://github.com/lhccong/fish-island-backend/blob/7c61b7861e99d3970beb34103c244b79e4de7d88/src/main/java/com/cong/fishisland/controller/chat/WebParserController.java#L13-L25
• https://github.com/lhccong/fish-island-backend/blob/7c61b7861e99d3970beb34103c244b79e4de7d88/src/main/java/com/cong/fishisland/service/impl/chat/WebParserServiceImpl.java#L28-L45
• https://hackmd.io/@hieuPenguinnn/fish-island-web-parse-unauth-ssrf
• https://www.vulncheck.com/advisories/fish-island-backend-through-commit-7c61b78-ssrf-via-api-web-parse