External Secrets Operator: Privilege escalation with secret overwriting

published 2026-05-08 6 mo ago modified 2026-10-06 33 d ago also GHSA-fq7h-9x26-6j22 , GO-2026-5377 , EUVD-2026-29191

cvss: 4.9; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 distros 1 links 2

go github.com/external-secrets/external-secrets/apis 2.4.1

govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42876 updated 2026-10-14 cvss 8.1

external-secrets-operator: External Secrets Operator: Privilege escalation via ExternalSecret resource creation

Red Hat All currently supported Red Hat products
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-12)

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.9	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N
GitHub	3.1	4.9	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:N

Affected packages

ecosystem	package	affected	fixed in
go	github.com/external-secrets/external-secrets/apis	>=0.1.0, <2.4.1 all versions	2.4.1

Affected products

external-secrets external-secrets

Classification

Weakness

CWE-285 Improper Authorization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary