CVE-2026-27965
Vitess users with backup storage access can gain unauthorized access to production deployment environments
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
vitess.io/vitessReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Vitess is a database clustering system for horizontal scaling of MySQL. Prior to versions 23.0.3 and 22.0.4, anyone with read/write access to the backup storage location (e.g. an S3 bucket) can manipulate backup manifest files so that arbitrary code is later executed when that backup is restored. This can be used to provide that attacker with unintended/unauthorized access to the production deployment environment — allowing them to access information available in that environment as well as run any additional arbitrary commands there. Versions 23.0.3 and 22.0.4 contain a patch. Some workarounds are available. Those who intended to use an external decompressor then can always specify that decompressor command in the --external-decompressor flag value for vttablet and vtbackup. That then overrides any value specified in the manifest file. Those who did not intend to use an external decompressor, nor an internal one, can specify a value such as cat or tee in the --external-decompressor flag value for vttablet and vtbackup to ensure that a harmless command is always used.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | vitess.io/vitess | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vitess.io/vitess. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of vitess.io/vitess has shipped for CVE-2026-27965 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-27965 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-27965. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-27965 in your dependencies?
O3 detects CVE-2026-27965 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.