CVE-2026-27965: 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 back...

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.

Metrics

CVSS 3.1

9.9/10

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

CVSS 4.0

8.4/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.42%

33.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-78

Affected Software

Vendor	Product	Versions
Linuxfoundation	Vitess	< 22.0.4
Linuxfoundation	Vitess	>= 23.0.0, < 23.0.3

References

https://github.com/vitessio/vitess/commit/4c0173293907af9cb942a6683c465c3f1e9fdb5cPatch
https://github.com/vitessio/vitess/issues/19459Issue Tracking
https://github.com/vitessio/vitess/pull/19460Issue Tracking, Patch
https://github.com/vitessio/vitess/security/advisories/GHSA-8g8j-r87h-p36xMitigation, Patch, Vendor Advisory

Timeline

Published: Feb 26, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-27965?

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.

How severe is CVE-2026-27965?

CVE-2026-27965 has a CVSS score of 8.4/10 (HIGH severity). The EPSS model estimates a 0.42% probability of exploitation in the next 30 days.

How do I fix CVE-2026-27965?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.