Evidence used
- No CISA KEV confirmation is currently recorded.
- A structured source references public exploit or proof-of-concept material.
- EPSS is 0.69% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-27965High confidence
Vitess users with backup storage access can gain unauthorized access to production deployment environments
vitessio · vitess
Official source article: GitHub GHSA-8G8J-R87H-P36X ↗. Check the applicable product and release in the original source.
8.4HighCVSS 4.0
Within 7 days
Patch availableHigh technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Critical, raised one band.upgradedsince 26 Feb 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Increase monitoring for the attack path and post-exploitation behaviour described in the report.
Verification
- Confirm that the asset runs vitessio vitess and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Open-source package ranges1 source-attributed range
These OSV and GitHub advisory ranges apply only to the named package and ecosystem. A listed fixed version is not a universal product patch or proof that an update is installed.
| Ecosystem and package | Affected range | First fixed version | Evidence |
|---|---|---|---|
| govitess.io/vitess | <= 0.23.2 | Not stated | GitHub advisory ↗upstream repository advisory · 26 Feb 2026 |
High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.
Patch available01
What, why and how
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.
What
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.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.
What
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.
Why
Untrusted input is incorporated into an operating-system command without safe parameter handling.
How
An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material Reference recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.
- Likely attack path
- a network path → Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- High: elevated access is required
- User interaction
- Passive interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-78 ↗
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:LCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VALowVulnerable-system availability: A successful attack can cause a limited loss.SCLowSubsequent-system confidentiality: A successful attack can cause a limited loss.SILowSubsequent-system integrity: A successful attack can cause a limited loss.SALowSubsequent-system availability: A successful attack can cause a limited loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04
Evidence and provenance
Published 26 Feb 2026 · Last source change 26 Feb 2026, 19:32 UTC · CWE-78 · Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-8818
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.