CVE-2026-39852: Quarkus broken access control (CVSS 8.2)

Description

Quarkus is a Java framework for building cloud-native applications. In versions prior to 3.20.6.1, 3.27.3.1, 3.33.1.1, 3.35.1.1, 3.34.7, and 3.35.2, a path normalization inconsistency between the security layer and the routing layer allows unauthenticated or lower-privileged users to bypass HTTP path-based authorization policies. Quarkus's security layer performs authorization checks on the raw URL path which preserves matrix parameters (semicolons), while RESTEasy Reactive's routing layer strips matrix parameters before matching endpoints. An attacker can append a semicolon and arbitrary text to a request URL (e.g., /api/admin;anything) to bypass policies protecting /api/admin while still routing to the protected endpoint. This issue has been fixed in versions 3.20.6.1, 3.27.3.1, 3.33.1.1, 3.35.1.1, 3.34.7, and 3.35.2.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityLow

AvailabilityNone

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

Affected products

Quarkus≥ 3.21.0 < 3.27.3.1 · ≥ 3.28.0 < 3.33.1.1 · ≥ 3.34.0 < 3.34.7 · ≥ 3.35.0 < 3.35.2

Remediation

Fixed in

Quarkus≥ 3.27.3.1

Patch & vendor advisories

https://github.com/quarkusio/quarkus/security/advisories/GHSA-rc95-pcm8-65v9

References

and 1 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-39852 being actively exploited?

CVE-2026-39852 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.63%.

How severe is CVE-2026-39852?

CVE-2026-39852 has a CVSS 3.1 base score of 8.2, rated high. EPSS estimates a 0.63% probability of exploitation.

Which products are affected by CVE-2026-39852?

Affected products include Quarkus.

How do I fix CVE-2026-39852?

Upgrade affected software to a fixed version, for example Quarkus 3.27.3.1 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-39852 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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