Is there a public exploit for CVE-2026-126367?

No public exploit for CVE-2026-126367 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-126367?

CVE-2026-126367 scores CVSS 4.8 (v3.1), rated medium. EPSS puts the chance of exploitation in the next 30 days at 0%.

What does CVE-2026-126367 affect?

CVE-2026-126367 affects grpc @grpc/grpc-js-xds.

4.8 Medium

@grpc/grpc-js: safe_regex incorrectly applies partial string matching for patterns with alternation

CVE-2026-126367

Summary The StringMatcher/PathMatcher for saferegex builds its RE2 as ^${regex}$ with no surrounding group. Because alternation has the lowest precedence, a pattern "a|b|c" compiles to /^a|b|c$/ -- "starts with a" OR "contains b" OR "ends with c" instead of a full match of the whole value. Configurations with saferegex matchers that use a regex alternation (a natural way to list methods or service identities) therefore apply partial string matches. This impacts route selection, xDS credentials, and RBAC. Details src/matcher.ts: SafeRegexValueMatcher and PathSafeRegexValueMatcher both do ts this.targetRegexImpl = new RE2(^${targetRegex}$, 'u'); and apply() returns targetRegexImpl.test(value). With a top-level alternation the anchors bind only to the first/last branch. https://github.com/grpc/grpc-node/blob/e742b11bd8039f3dbea4cd29afdf5d95a8ba6b92/packages/grpc-js-xds/src/matcher.ts#L59 https://github.com/grpc/grpc-node/blob/e742b11bd8039f3dbea4cd29afdf5d95a8ba6b92/packages/grpc-js-xds/src/matcher.ts#L232 src/route.ts (getPredicateForStringMatcher / getPredicateForHeaderMatcher) builds these for every saferegex StringMatcher/HeaderMatcher, and src/rbac.ts uses them for RBAC urlpath…

Assessment

CVSS: 4.8 (v3.1)
Severity: Medium
EPSS: 0% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 12 November 2026
Last updated: 12 November 2026
Affected: grpc · grpc-node · @grpc/grpc-js-xds
Weakness: CWE-625, CWE-863
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

At the source

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