CVE-2026-57958 Mixpost 2.6.0 - Reflected XSS via OAuth Callback Error Parameter
Unauthenticated attackers can execute arbitrary JavaScript in authenticated users' browsers via malicious OAuth callback URLs, leading to session hijacking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-57958?
CVE-2026-57958 is a medium-severity cross-site scripting vulnerability in inovector mixpost, published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-57958?
How do I fix CVE-2026-57958?
No fix has been published for CVE-2026-57958 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-57958 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-57958 exists.
Sources
Also known as GHSA-x4g3-x4c9-rjf8.