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CVE-2026-59396

DoS Vulnerability in UAA Related to JWKS URI Handling

CVSS score

6.9

EPSS probability

—

Risk score

0.7

Published

2 h ago

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

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Vulnerability description

DayBreach AI Explanation

Verified against sources

CVE-2026-59396: DoS Vulnerability in UAA Related to JWKS URI Handling

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

A denial-of-service vulnerability exists in Cloud Foundry UAA's private_key_jwt client-authentication mechanism [S0]. Retrieving and caching remote JWKS URI responses can trigger full deserialization of cached data during invalid authentication attempts, causing excessive CPU usage and potential Java heap exhaustion via OutOfMemoryError [S0].

Why does it matter?

This vulnerability allows attackers targeting authentication mechanisms to consume excessive resources and cause service disruptions [S0].

What should be done?

  • Follow official vendor advisories as the patch status is currently unknown [S0]
  • Review updates for the affected UAA and cf-deployment versions [S0]
Chain of evidence and sources2 verified claims

CVE-2026-59396, UAA'nın private_key_jwt mekanizmasında bir hizmet dışı bırakma (DoS) zafiyetidir [S0].

Geçersiz kimlik doğrulama denemeleri, önbelleğe alınmış verilerin tam seri durumdan çıkarılmasını tetikleyerek aşırı CPU kullanımına ve OutOfMemoryError hatasına yol açabilir [S0].

Show the technical text from the sources

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.

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-59396 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1Cloud FoundryUAA View
2Cloud Foundrycf-deployment View
Total affected vendors: 1|Products: 2

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
6.9CVSS V40MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD
6.9CVSS V4_0MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE CNA
4.9CVSS V31MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HNVD
4.9CVSS V3_1MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:HCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-59396 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-59396 weaknesses.

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsHigh
UserGerekmiyor

Official Sources and Advisories

CVSS Vector Radar Chart

6.9 / 10
Attack VectorNetworkComplexityLowPrivilegesHighUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

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CVE-2026-59396 · DoS Vulnerability in UAA Related to JWKS…