Paper/Archive/CVE-2026-126800

CVE-2026-126800

hydro-dev @hydrooj/ui-default — Hydro @hydrooj/ui-default before 4.59.1 Stored XSS via Markdown language- Class

CVSS 9.3 (CNA)9.3 / 10 × 3027.9 Not in CISA KEV+300.0 No EPSS score.000 × 200.0 No public exploit+100.0 SSVC exploitation: unknown+100.0

Description · from the CVE record

Hydro @hydrooj/ui-default before 4.59.1 contains a stored cross-site scripting vulnerability that allows registered users to inject script by placing double quotes in language- class tokens within markdown-it-xss.ts. Attackers can store a payload in their profile bio that executes when administrators or other users view it, stealing the non-httpOnly sid session cookie for session hijacking.

Affected

ProductAffectedFixed inSource

@hydrooj/ui-default< 4.59.14.59.1CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

VulnCheck (CNA)8.7CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

References

patchgithub.com/hydro-dev/Hydro/commit/3bae56fe8edddff12346bcb1c8281269c94688d8 writeupgithub.com/hydro-dev/Hydro/blob/3c8286dd1350fcd00412e95d5b056dbfed64edda/packages/ui-default/backendlib/markdown-it-xss.ts#L150-L157 writeupvul.yulun.ac.cn/20261107/hydro writeupvulncheck.com/advisories/hydro-hydrooj-ui-default-before-4.59.1-stored-xss-via-markdown-language-class