Vulnerability · Published Oct 30, 2026 · Assigned by VulnCheck

CVE-2026-119764Mythic 3.2.16 through 3.4.0.61 Stored XSS via Agent-Downloaded File Preview

Medium 6.8

In plain English

A medium-severity cross-site scripting in Mythic from its-a-feature. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.3%top 75.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Mythic 3.2.16 through 3.4.0.61 contains a stored cross-site scripting vulnerability that allows attackers controlling target endpoint files to run JavaScript in the Mythic UI origin by planting HTML in .pdf-named files. When an operator downloads the file and clicks Preview Media, content-sniffed HTML from /direct/view renders same-origin, stealing localStorage JWTs for full GraphQL and REST access.

Affected products (as reported)

Vendor	Product	Versions
its-a-feature	Mythic	3.2.16 – through 3.4.0.61

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

References

https://github.com/h00die/mythic_xss third-party-advisory
https://github.com/its-a-feature/Mythic/commit/f06b3ed2d1de6577744cc0b3146966c625685859 patch
https://github.com/its-a-feature/Mythic/blob/33a46d7db7e237458d7e20e7d3cfefef8112e590/MythicReactUI/src/components/pages/Callbacks/ResponseDisplayMedia.js#L335-L336 technical-description
https://github.com/its-a-feature/Mythic product
VulnCheck Advisory: Mythic 3.2.16 through 3.4.0.61 Stored XSS via Agent-Downloaded File Preview third-party-advisory