{"id":"CVE-2026-103321","aliases":["EUVD-2026-89800","GHSA-w4mv-4x7w-vpvv"],"status":"published","title":"MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","severity":{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.0036,"percentile":0.30172,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20","CWE-79"],"published":"2026-09-30T12:19:01Z","modified":"2026-10-28T02:31:06Z","products":[{"vendor":"misp","product":"misp"}],"references":[{"url":"https://github.com/MISP/MISP/commit/92c7ccc43","tags":["patch","fix"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-103321","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-w4mv-4x7w-vpvv"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103321.json","tags":["advisory"]},{"url":"https://github.com/MISP/MISP","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-103321","title":"MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","status":"published","published":"2026-09-30T12:19:01.829Z","modified":"2026-09-30T12:44:22.064Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-79","CWE-20"],"updated_at":"2026-11-02T13:34:37.420074Z"}],"euvd":[{"id":"EUVD-2026-89800","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","status":"published","published":"2026-09-30T12:19:01Z","modified":"2026-09-30T12:44:22Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N","level":"high"}],"updated_at":"2026-11-02T17:27:50.183381Z"}],"ghsa":[{"id":"GHSA-w4mv-4x7w-vpvv","title":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n...","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","status":"published","published":"2026-09-30T15:31:24Z","modified":"2026-09-30T15:31:32Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:12:36.462442Z"}],"nvd":[{"id":"CVE-2026-103321","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","status":"published","published":"2026-09-30T13:17:18.463Z","modified":"2026-09-30T13:17:18.603Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"}],"cwes":["CWE-20","CWE-79"],"updated_at":"2026-11-02T14:12:52.759595Z"}],"osv":[{"id":"CVE-2026-103321","title":"MISP Stored Cross-Site Scripting (XSS) via Unvalidated Event Graph Preview Image","description":"MISP contains a stored cross-site script (XSS) vulnerability in the event graph preview feature.\n\nThe event graph preview image field was accepted and stored without server-side validation. On the client side, the stored value was rendered into an HTML img element's src attribute via string concatenation, allowing a crafted value to break out of the attribute context and inject arbitrary script.\n\nPreconditions:\n\n- An authenticated MISP user with the ability to create or modify an event graph entry.\n\n- A second user (the victim) who views the event graph and triggers the preview popover.\n\nImpact:\n\n- Execution of arbitrary JavaScript in the victim's browser within the MISP application context.\n\n- Potential theft of session tokens, cookies, or sensitive data accessible to the victim's browser.\n\n- Potential for performing actions on behalf of the victim within the MISP application.\n\nAffected: MISP versions prior to the fix (commit applied after v2.5.48).","status":"published","published":"2026-09-30T12:19:01.829Z","modified":"2026-10-28T02:31:06.683532609Z","cvss":[{"version":"4.0","score":8.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N","level":"high"}],"cwes":["CWE-20","CWE-79"],"updated_at":"2026-11-02T15:44:54.236592Z"}]}}