How severe is CVE-2026-27965?

No CVSS score has been assigned to CVE-2026-27965 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-27965?

CVE-2026-27965 affects the following packages: vitess.io/vitess (Go). Ecosystems affected: Go.

How do I fix CVE-2026-27965?

The records we use list no patched version of vitess.io/vitess for CVE-2026-27965. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

How do I detect CVE-2026-27965 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vitess.io/vitess, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-27965 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-27965 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-27965 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-27965?

CVE-2026-27965 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 41th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-27965?

CVE-2026-27965 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-27965 published, and has it been updated?

CVE-2026-27965 was published on February 26, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-27965 — vitess

Fix: vitessio/vitess@4c01732

CVE-2026-27965 is a OS Command Injection vulnerability in vitess.io/vitess. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

Vitess users with backup storage access can gain unauthorized access to production deployment environments

Also known asGHSA-8g8j-r87h-p36xGO-2026-4567

Published

Feb 26, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

See advisory

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs41th percentile — riskier than 41% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

🐹vitess.io/vitess

Real-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

Impact

Any user 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.

Patches

Fixes are expected to be released with versions v23.0.3 and v22.0.4 See fix commit at https://github.com/vitessio/vitess/commit/4c0173293907af9cb942a6683c465c3f1e9fdb5c

Workarounds

If maintainers intended to use an external decompressor then they 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.

If maintainers did not intend to use an external decompressor, nor an internal one, then they 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.

References

Users can read more about the issue here: https://github.com/vitessio/vitess/issues/19459

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`vitess.io/vitess`	all versions	No fix

Affected Products

1 product · 2 configurations

Application

vitesslinuxfoundation

≥ 23.0.0 && < 23.0.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vitess.io/vitess, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of vitess.io/vitess for CVE-2026-27965. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Impact Any user 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. ### Patches Fixes are expected to be released with versions v23.0.3 and v22.0.4 See fix commit at https://github.com/vitessio/vitess/commit/4c0173293907a