Vitess vttablet /twopcz reflected XSS

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-104252: 1.17% estimated exploitation activity in the next 30 days; percentile 67.56 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

From: xylove21 To: security@vitess.io Subject: [Security Report] Vitess vttablet /twopcz reflected XSS Date: Tue, 24 Jun 2026 14:30:00 +0800 Summary The twopczHandler in go/vt/vttablet/tabletserver/twopcz.go (line 185) reflects the Action and dtid form values directly into the HTML response body via fmt.Fprintln(w, msg) — without HTML escaping. The response is served as text/html; charset=utf-8, and Vitess's default acl policy is allow-all, so the endpoint is reachable by anyone who can hit the vttablet's HTTP port (default 15999, multiplexed with gRPC and MySQL wire-protocol ports). A crafted Action or dtid value yields a reflected XSS that executes in the operator's browser with same-origin access to the vttablet's debug endpoints. This includes /queryz (live query plans), /querylogz (recent queries with bound values), /txlogz (transactions), /debug/env (environment variables — may include MySQL/topology credentials), /debug/vars (expvar stats), and /debug/pprof/ if enabled. The…

Published by the source

15 Oct 2026, 20:16 UTC

Last modified by the source

15 Oct 2026, 20:30 UTC

Source last checked

26 Oct 2026, 15:32 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v75v-6fpf-gvw8

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-v75v-6fpf-gvw8

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# Patch Next advisory brief: CVE-2026-104252

Advisory: Vitess vttablet /twopcz reflected XSS
IDs: CVE-2026-104252, GHSA-v75v-6fpf-gvw8
Record: https://patchnext.com/advisories/cve-2026-104252 (revision 2, source checked 26 Oct 2026, 15:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: vitess.io/vitess 0.24.2, 0.23.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go vitess.io/vitess: affected < 0.23.5; >= 0.24.0, < 0.24.2; fixed in 0.24.2, 0.23.5

## Suggested inspection (read-only)
- Go vitess.io/vitess: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on vitess.io/vitess.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-v75v-6fpf-gvw8 (OSV record GHSA-v75v-6fpf-gvw8 lists affected ranges: Go vitess.io/vitess >=0 =0.24.0 <0.24.2 (fixed))
- Verified: https://github.com/advisories/GHSA-v75v-6fpf-gvw8 (GitHub-reviewed advisory GHSA-v75v-6fpf-gvw8 lists affected ranges: Go vitess.io/vitess >=0 =0.24.0 <0.24.2)

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