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

Status: published. Published: 2026-10-30. Updated: 2026-11-05.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/its-a-feature/Mythic/commit/f06b3ed2d1de6577744cc0b3146966c625685859

## Affected products and versions

- its-a-feature / Mythic (its-a-feature/Mythic): ≥ 3.2.16; ≤ 3.4.0.61 (affected, custom). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.4 (high); CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.32% as of 2026-11-04; percentile 24.74%

- SSVC: exploitation poc; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-79

## Exploit evidence

- exploit: https://github.com/h00die/mythic_xss (ADP: CISA-ADP)

## References

- https://github.com/h00die/mythic_xss (CNA: VulnCheck; third-party-advisory)

- https://github.com/its-a-feature/Mythic/commit/f06b3ed2d1de6577744cc0b3146966c625685859 (CNA: VulnCheck; patch)

- https://github.com/its-a-feature/Mythic/blob/33a46d7db7e237458d7e20e7d3cfefef8112e590/MythicReactUI/src/components/pages/Callbacks/ResponseDisplayMedia.js#L335-L336 (CNA: VulnCheck; technical-description)

- https://github.com/its-a-feature/Mythic (CNA: VulnCheck; product)

- https://www.vulncheck.com/advisories/mythic-3.2.16-through-3.4.0.61-stored-xss-via-agent-downloaded-file-preview (CNA: VulnCheck; third-party-advisory)

- https://github.com/h00die/mythic_xss (ADP: CISA-ADP; exploit)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-119764; retrieved 2026-11-05; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-119764; retrieved 2026-11-05; source updated Not reported

Revision: 4d9639e32831ee1712a4db1b134f86789517870090f65fdc3e1b32ac0c34c7b1

Canonical: https://y2.dev/cve/CVE-2026-119764

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.