Evidence used
- No CISA KEV confirmation is currently recorded.
- EPSS is 0.18% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-59357High confidence
Self-UAA OIDC Configuration allows JWT injection to establish unauthorized sessions
Cloud Foundry · UAA
6.5MediumCVSS 4.0
Scheduled
Patch availableMedium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityMedium→Operational priority:Medium, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Cloud Foundry UAA and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available01
What, why and how
Insufficient verification of data authenticity (CWE-345) in the external OIDC login callback in Cloud Foundry UAA v4.5.0 to v79.6.0 (inclusive) allows an authenticated UAA user to bypass the OAuth authorization-code exchange and establish an authenticated external-OIDC browser session, via submitting a UAA access token or a cross-client ID token as the callback’s id_token parameter. The issue only manifests when a UAA zone is configured with an OIDC identity provider whose issuer exactly matches that zone’s own /oauth/token endpoint (a “self-UAA” OIDC configuration). In this configuration, the callback takes a supplied id_token directly instead of requiring the authorization code exchange, and does not verify that the token was actually issued as an ID token for the specific self-OIDC relying-party client. An attacker holding any valid UAA JWT for themselves — including a plain access token with only uaa.user scope, or a valid ID token issued to an unrelated client such as cf — can present it as the callback’s id_token and be authenticated into a mapped local (“shadow”) account. Because the resulting session is not verified against the originating token’s true audience or user_id, its effective privilege depends entirely on the shadow account’s group memberships, which can include administrative scopes such as clients.write. Exploitation requires a valid UAA user JWT, a valid browser login state for the target zone, and the presence of a self-referential OIDC provider configuration — this is not a pre-authentication vulnerability, and does not by itself grant privileges beyond those already held by the mapped shadow account.
What
Insufficient verification of data authenticity (CWE-345) in the external OIDC login callback in Cloud Foundry UAA v4.5.0 to v79.6.0 (inclusive) allows an authenticated UAA user to bypass the OAuth authorization-code exchange and establish an authenticated external-OIDC browser session, via submitting a UAA access token or a cross-client ID token as the callback’s id_token parameter. The issue only manifests when a UAA zone is configured with an OIDC identity provider whose issuer exactly matches that zone’s own /oauth/token endpoint (a “self-UAA” OIDC configuration). In this configuration, the callback takes a supplied id_token directly instead of requiring the authorization code exchange, and does not verify that the token was actually issued as an ID token for the specific self-OIDC relying-party client. An attacker holding any valid UAA JWT for themselves — including a plain access token with only uaa.user scope, or a valid ID token issued to an unrelated client such as cf — can present it as the callback’s id_token and be authenticated into a mapped local (“shadow”) account. Because the resulting session is not verified against the originating token’s true audience or user_id, its effective privilege depends entirely on the shadow account’s group memberships, which can include administrative scopes such as clients.write. Exploitation requires a valid UAA user JWT, a valid browser login state for the target zone, and the presence of a self-referential OIDC provider configuration — this is not a pre-authentication vulnerability, and does not by itself grant privileges beyond those already held by the mapped shadow account.
Why
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
Insufficient verification of data authenticity (CWE-345) in the external OIDC login callback in Cloud Foundry UAA v4.5.0 to v79.6.0 (inclusive) allows an authenticated UAA user to bypass the OAuth authorization-code exchange and establish an authenticated external-OIDC browser session, via submitting a UAA access token or a cross-client ID token as the callback’s id_token parameter. The issue only manifests when a UAA zone is configured with an OIDC identity provider whose issuer exactly matches that zone’s own /oauth/token endpoint (a “self-UAA” OIDC configuration). In this configuration, the callback takes a supplied id_token directly instead of requiring the authorization code exchange, and does not verify that the token was actually issued as an ID token for the specific self-OIDC relying-party client. An attacker holding any valid UAA JWT for themselves — including a plain access token with only uaa.user scope, or a valid ID token issued to an unrelated client such as cf — can present it as the callback’s id_token and be authenticated into a mapped local (“shadow”) account. Because the resulting session is not verified against the originating token’s true audience or user_id, its effective privilege depends entirely on the shadow account’s group memberships, which can include administrative scopes such as clients.write. Exploitation requires a valid UAA user JWT, a valid browser login state for the target zone, and the presence of a self-referential OIDC provider configuration — this is not a pre-authentication vulnerability, and does not by itself grant privileges beyond those already held by the mapped shadow account.
Why
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
How
An attacker operating through a network path may attempt exploitation when the stated preconditions are met. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- a network path → Insufficient Verification of Data Authenticity → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- Active interaction required
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Not a CVSS 4.0 base metric
- Weakness
?
CWE means Common Weakness Enumeration: a standard category for the underlying weakness. - CWE-345 ↗
CWE-345: Insufficient Verification of Data Authenticity. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:PCommon Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATPresentAttack requirements: A particular deployment or execution condition must be present.PRNonePrivileges required: The attacker does not need an account or existing privileges.UIActiveUser interaction: A user must take a deliberate action for exploitation to succeed.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.- Post-exploitation / living off the land
- Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Patch available
- Action
- Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 6 Oct 2026 · Last source change 6 Oct 2026, 11:49 UTC · CWE-345 · Insufficient Verification of Data Authenticity
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-10-06
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-92989
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD awaiting enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- ENISA EUVD mappingEUVD-2026-92989 was added to the official ENISA EUVD mapping for this CVE.ENISA EUVD ↗
- Before
- not recorded
- After
- {"euvdId":"EUVD-2026-92989"}
- Catalogue recordCVE added to the BlackTree catalogue.CNA ↗
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.