CVE-2026-39350: medium-severity vulnerability in istio
Istio AuthorizationPolicy Incorrect Regex Matching of Dots in serviceAccounts Fields Allows Policy Bypass
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.4epss 0.2%
Istio is an open platform to connect, manage, and secure microservices. In versions 1.25.0 through 1.27.8, 1.28.0 through 1.28.5, 1.29.0, and 1.29.1, the serviceAccounts and notServiceAccounts fields in AuthorizationPolicy incorrectly interpret dots (.) as a regular expression matcher. Because . is a valid character in a service account name, an AuthorizationPolicy ALLOW rule targeting a service account such as cert-manager.io also matches cert-manager-io, cert-managerXio, etc. A DENY rule targeting the same name fails to block those variants. Fixes are available in versions 1.29.2, 1.28.6, and 1.27.9.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Affected products
istio · istioRelated CVEs — istio
In the same product, most dangerous first.
CVE-2022-23635HIGHUnauthenticated control plane denial of service attack in IstioEPSS 1.7%CVE-2022-24726HIGHUnauthenticated control plane denial of service attack in IstioEPSS 1.6%CVE-2022-39278HIGHIstio vulnerable to denial of service attack due to Golang Regex LibraryEPSS 1.4%CVE-2021-39155HIGHAuthorization Policy Bypass Due to Case Insensitive Host ComparisonEPSS 1.2%CVE-2022-31045HIGHIll-formed headers may lead to unexpected behavior in IstioEPSS 1.2%CVE-2021-39156HIGHFragments in Path May Lead to Authorization Policy BypassEPSS 1.2%