{"id":"CVE-2026-56735","revision":null,"records":[{"revision":"47c95867813c42eaab2d4118f5a6b5e6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-56735","aliases":[],"title":"Zammad: Improper neutralization of `srcset` attribute in IMG tags in Zammad","description":"Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2 and 7.1.0, zammad's HTML sanitizer (HtmlSanitizer::Strict) blocks external URLs in  to prevent remote content loading, but the srcset attribute, also allowlisted for , is not subject to the same check. This oversight allows an attacker to embed arbitrary external URLs in the srcset attribute just by sending an e-mail, effectively bypassing the external content protection. When an agent views the ticket containing the malicious srcset, the browser will silently load the attacker-controlled URL, resulting in the leakage of the agent's IP address, User-Agent, Referer, and the exact time the ticket was viewed. HtmlSanitizer::Strict got extended to block external URLs in the srcset attribute of  tags. This was done to prevent tracking pixels and external content loading, which could compromise user privacy. This issue is fixed in versions 7.0.2 and 7.1.0.","state":0,"publishedAt":"2026-09-25T17:04:03.247+00:00","modifiedAt":"2026-09-25T19:06:35.154+00:00","affected":[{"ecosystem":"Vendor product","name":"zammad","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"zammad\",\n                    \"product\": \"zammad\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 7.0.2\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","score":5.3,"severity":"MEDIUM"}],"references":["https://github.com/zammad/zammad/security/advisories/GHSA-7fwx-3xr4-qm6w","https://github.com/zammad/zammad/commit/02c1ff8dc65961352dc047013bece9dff1f2ffb7","https://github.com/zammad/zammad/releases/tag/7.0.2","https://github.com/zammad/zammad/releases/tag/7.1.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-56735","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-56735","identifiers":["CVE-2026-56735"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-12T09:55:31.2947259+00:00","complete":true,"records":1779,"lastAttemptAt":"2026-11-12T09:55:31.2947259+00:00","lastSuccessAt":"2026-11-12T09:55:31.4790381+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:31.4790388+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-64752486c567b55b31fb0d7225f5222bcd0019564ac0ac5f0649e242c7b19299-597d2a846bb8b004ef04143ee27b4f2061367ce1f574db03c0eec66ce3f0654b","complete":true,"records":424644,"lastAttemptAt":"2026-11-12T10:53:33.7939567+00:00","lastSuccessAt":"2026-11-12T10:53:33.7645522+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:53:33.7939567+00:00","snapshotPublishedAt":"2026-11-12T10:28:09+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-9db698e4659747149ec1092e3d34a5a1","complete":true,"records":13764,"lastAttemptAt":"2026-11-12T09:56:01.66177+00:00","lastSuccessAt":"2026-11-12T09:56:01.656+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:56:01.656+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13817,"expectedIdentifiers":13817,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-12T09:55:31.2947259+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-12T09:55:31.2947259+00:00","lastSuccessAt":"2026-11-12T09:55:31.4798179+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:31.4798182+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-1a7cc780d036453fb794b7d2d385de9d","complete":false,"records":13764,"lastAttemptAt":"2026-11-12T09:55:57.1306222+00:00","lastSuccessAt":"2026-11-12T09:55:57.111+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:57.111+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13313,"expectedIdentifiers":13817,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-12T09:55:26.640208+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:26.640208+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-12T10:53:33.9269183+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-12T10:53:33.9269183+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-f46f74c6a30a9b6e4cfb481719c6d35521ebec2d53ebf163223d093ae587eb9d","complete":true,"records":3106,"lastAttemptAt":"2026-11-12T09:55:31.2553322+00:00","lastSuccessAt":"2026-11-12T09:55:31.1176285+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:31.2553322+00:00","snapshotPublishedAt":"2026-11-12T09:48:13+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-ef2ecb421099c77d2be989a707f600817e68bbc84b134f8c0b574289c6a9dbb4","complete":true,"records":231700,"lastAttemptAt":"2026-11-12T10:53:40.0952115+00:00","lastSuccessAt":"2026-11-12T09:55:25.0439596+00:00","error":null,"lastVerifiedAt":"2026-11-12T09:55:26.5140063+00:00","snapshotPublishedAt":"2026-11-12T09:33:09+00:00","importing":true,"stagedRecords":106500,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}