{"cve":"CVE-2026-34984","nvd":{"published":"2026-04-14T03:16:08.530","modified":"2026-06-17T10:39:56.500","status":"Analyzed","description":"External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Versions 2.2.0 and below contain a vulnerability in runtime/template/v2/template.go where the v2 template engine removes env and expandenv from Sprig's TxtFuncMap() but leaves the getHostByName function accessible to user-controlled templates. Since ESO executes templates within the controller process, an attacker who can create or update templated ExternalSecret resources can invoke controller-side DNS lookups using secret-derived values. This creates a DNS exfiltration primitive, allowing fetched secret material to be leaked via DNS queries without requiring direct outbound network access from the attacker's workload. The impact is a confidentiality issue, particularly in environments where untrusted or lower-trust users can author templated ExternalSecret resources and the controller has DNS resolution capability. This issue has been fixed in version 2.3.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","score":7.1},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","score":6.5},"cwes":["CWE-200"],"references":["https://github.com/external-secrets/external-secrets/commit/6800989bdc12782ca2605d3b8bf7f2876a16551a","https://github.com/external-secrets/external-secrets/releases/tag/v2.3.0","https://github.com/external-secrets/external-secrets/security/advisories/GHSA-r2pg-r6h7-crf3"],"products":["external-secrets:external_secrets_operator"],"source":"nvd","synced_at":"2026-10-19T22:30:49.762551342+00:00"},"epss":{"cve":"CVE-2026-34984","score":0.00262,"percentile":0.18093,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-r2pg-r6h7-crf3","url":"https://osv.dev/vulnerability/GHSA-r2pg-r6h7-crf3","summary":"External Secrets Operator has DNS-based secret exfiltration via getHostByName in External Secrets v2 template engine","modified":"2026-09-10T03:51:02.919188766Z","packages":[{"ecosystem":"Go","name":"github.com/external-secrets/external-secrets","purl":"pkg:golang/github.com/external-secrets/external-secrets","ranges":["<1.3.3-0.20260331202714-6800989bdc12"],"fixed":["1.3.3-0.20260331202714-6800989bdc12"]},{"ecosystem":"Go","name":"github.com/external-secrets/external-secrets","purl":"pkg:golang/github.com/external-secrets/external-secrets","ranges":[">=2.0.0 <=2.2.0"],"fixed":[]}]},{"id":"GO-2026-5602","url":"https://osv.dev/vulnerability/GO-2026-5602","summary":"External Secrets Operator has DNS-based secret exfiltration via getHostByName in External Secrets v2 template engine in github.com/external-secrets/external-secrets","modified":"2026-06-25T23:01:35.666966028Z","packages":[{"ecosystem":"Go","name":"github.com/external-secrets/external-secrets","purl":"pkg:golang/github.com/external-secrets/external-secrets","ranges":["<1.3.3-0.20260331202714-6800989bdc12"],"fixed":["1.3.3-0.20260331202714-6800989bdc12"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}