CVE-2026-40965Network attack vector

JWT signing-key disclosure via public endpoint

Published Jun 1, 2026 · Updated Jun 1, 2026

Information disclosure in Cloud Foundry UAA 76.12.0 through 78.12.0 allows remote attackers to obtain EC JWT signing keys. The /token_keys response serializes EC private key components with the intended public verification material instead of filtering them out. Exposure requires EC rather than RSA JWT signing and permits token forgery in UAA Release and cf-deployment deployments.

CVSS severity10.0
Critical
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Cloud Foundry UAA 76.12.0 through 78.12.0 allows remote attackers to obtain EC JWT signing keys. The /token_keys response serializes EC private key components with the intended public verification material instead of filtering them out. Exposure requires EC rather than RSA JWT signing and permits token forgery in UAA Release and cf-deployment deployments.

The record

CVE
CVE-2026-40965
Published
Jun 1, 2026
Updated
Jun 1, 2026
Vendor
Cloud Foundry Foundation
Product
cf-deployment
Classifications
CWE-200, T1552.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=30.0.0 <56.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Cloud Foundry Foundation · cf-deploymentversion=30.0.0 <56.1.0
Cloud Foundry Foundation · UAA Releaseversion=76.12.0 <78.13.0

Published CVSS scores

10.0Cloud Foundry FoundationCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
10.0Cloud Foundry FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1552.004Unsecured Credentials: Private Keys

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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