CVE-2026-39350

MEDIUM

Istio AuthorizationPolicy Incorrect Regex Matching of Dots in serviceAccounts Fields Allows Policy Bypass

Title source: cna
STIX 2.1

Description

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.

References (1)

Scores

CVSS v3 5.4
EPSS 0.0001
EPSS Percentile 1.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-185 CWE-863
Status published
Products (5)
istio/istio 1.25.0 - 1.27.9
istio/istio >= 1.25.0, < < 1.27.9
istio/istio >= 1.28.0, < 1.28.6
istio/istio >= 1.29.0, < 1.29.2
istio.io/istio 0.0.0-20241024090207-0bf27d49ba4b - 0.0.0-20260403004500-692e460c342dGo
Published Apr 15, 2026
Tracked Since Apr 16, 2026