TI-2026-82962 Aliases CVE-2026-59396 GHSA-xf4x-4c6x-9xm2

Denial of service in Cloud Foundry UAA via JWKS URI handling

LOW 30CWE-400Published 2026-10-30 · Updated 2026-10-30

Key facts

Attack vector: Network
Privileges required: High
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-400.

Summary

Cloud Foundry UAA from 76.23.0 before 79.9.0 and cf-deployment before 60.11.0 are affected. The private_key_jwt client authentication caches remote JWKS data, and invalid authentication attempts force full deserialization of that cached data (CWE-400). An attacker with write access to clients or a compromised endpoint can send anonymous requests that repeatedly parse large cached objects, exhausting CPU and Java heap memory with OutOfMemoryError and making the service unavailable.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Description from the CNA

A denial-of-service vulnerability exists in UAA's private_key_jwt client-authentication mechanism. When UAA retrieves a remote JWKS URI, it caches the response. Invalid authentication attempts can trigger full deserialization of this cached data. An attacker with prerequisites (write access to clients or a compromised endpoint) can send anonymous requests that force repeated parsing of large cached objects, causing excessive CPU usage and potential Java heap exhaustion via OutOfMemoryError, resulting in service unavailability.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00287 21st percentileScored 2026-11-07

Fix Fixed UAA (Cloud Foundry): 79.9.0cf-deployment (Cloud Foundry): 60.11.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Cloud Foundry	UAA	76.23.0 to before 79.9.0	79.9.0	Patch available	CNA
Cloud Foundry	cf-deployment	before 60.11.0	60.11.0	Patch available	CNA

UAA VendorCloud Foundry Affected 76.23.0 to before 79.9.0 Fixed in 79.9.0 Patch available CNA
cf-deployment VendorCloud Foundry Affected before 60.11.0 Fixed in 60.11.0 Patch available CNA

Remediation

Upgrade Cloud Foundry UAA to 79.9.0 and cf-deployment to 60.11.0.

Written with Claude Haiku 5.5 from the sources below · 2026-10-30

Fix · CNA UAA (Cloud Foundry) Fixed in 79.9.0
Fix · CNA cf-deployment (Cloud Foundry) Fixed in 60.11.0

Timeline

2026-10-30 Threatist record created from CVE-2026-59396
2026-10-30 Alias added: GHSA-xf4x-4c6x-9xm2
2026-10-30 CISA SSVC decision points changed
2026-10-30 Priority changed: MEDIUM → LOW
2026-10-30 Weakness changed · CISA ADP

References

Other 1

https://www.cloudfoundry.org/blog/cve-2026-59396-dos-vulnerability-in-uaa-related-to-jwks-uri-handling-2/

TI-2018-11240 UAA Privilege Escalation CVSS 3.0CRITICAL 9.9
TI-2018-01169 Log Cache logs UAA client secret on startup CVSS 3.0CRITICAL 9.8
TI-2018-07868 Cloud Foundry UAA MFA does not prevent brute force of MFA code CVSS 3.0CRITICAL 9.8
TI-2026-18259 Cloud Foundry UAA SAML 2.0 Signature Bypass CVSS 3.1HIGH 8.6
TI-2019-02813 Java Projects using HTTP to fetch dependencies CVSS 3.1CRITICAL 9.8
TI-2024-24613 Authentication bypass by spoofing in Cloud Foundry haproxy-boshrelease CVSS 3.1CRITICAL 9.1

See all 83 →

Sources

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