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Vulnerability · Published Sep 1, 2026 · Assigned by redhat

CVE-2026-49329Openshift/oauth-server: openshift/oauth-server: quadratic-time dos via accept-language header underscore bypass on unauthenticated login endpoints

High 7.5

In plain English

A high-severity security flaw in Red Hat OpenShift Container Platform 4.14 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 45.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

A flaw was found in openshift/oauth-server. The OAuth login and error page endpoints pass the unauthenticated Accept-Language header to golang.org/x/text/language.ParseAcceptLanguage() without input validation. A bypass of the CVE-2022-32149 mitigation exists: the upstream guard counts only '-' characters but the internal BCP 47 scanner aliases '_' to '-' after the guard check. An unauthenticated attacker can send a crafted Accept-Language header using '_' separators to trigger quadratic-time parsing, consuming excessive CPU and denying authentication to all cluster users.

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat OpenShift Container Platform 4.14 see references
Red Hat Red Hat OpenShift Container Platform 4.15 see references
Red Hat Red Hat OpenShift Container Platform 4.16 see references
Red Hat Red Hat OpenShift Container Platform 4.18 see references
Red Hat Red Hat OpenShift Container Platform 4.19 see references
Red Hat Red Hat OpenShift Container Platform 4.20 see references
Red Hat Red Hat OpenShift Container Platform 4.21 see references
Red Hat Red Hat OpenShift Container Platform 4.22 see references
Red Hat Red Hat OpenShift Container Platform 5 see references

Weakness: CWE-407 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References