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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Authenticate as low-privilege OAuth2 client
  2. Delivery
    Introspect access token (allowed_scopes enabled)
  3. Exploit
    Send revocation request in timing window
  4. Execution
    Stale token re-served from cache
  5. Impact
    Temporary authentication-flow disruption

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V7 - Session Management Session expiration enforcement
Exploitation Conditions

Exploitation requires the allowed_scopes configuration to be enabled on the affected WSO2 product - this is the exact prerequisite named in the advisory; default deployments without this setting are not affected. The attacker must be an authenticated OAuth2 client (CVSS PR:L) able to call both the token introspection and token revocation endpoints, and must hit a narrow ordering window where a token is introspected immediately before its revocation request (reflected as AC:H). Limiting factors: no confidentiality or integrity impact is possible (C:N/I:N), the re-issued token is rejected for API authorization, the effect lasts only for the cache lifetime until the entry is cleared, and the condition depends on a non-default configuration plus valid client credentials.

Impact

This is a low-severity, low-priority issue and the signals are internally consistent. The vendor-supplied CVSS:3.1 vector (AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L, base 3.1) describes a network-reachable but authenticated (PR:L) flaw with high attack complexity (AC:H) whose only impact is a low availability effect (C:N, I:N, A:L) - no confidentiality or integrity loss. The vuln.today Decision label is 'monitor', the lowest urgency tier, and there is no CISA KEV listing, no EPSS score supplied, and no public exploit identified at time of analysis. All signals agree: this is a correctness/availability defect in OAuth2 token-revocation caching, not a security-critical access-control bypass. The description explicitly states the re-issued token is NOT honored for API authorization, so the real-world harm is limited to a transient authentication-flow disruption rather than unauthorized access. Note one data gap: EPSS is not provided in the input, so probabilistic exploitation likelihood cannot be quantified, but given AC:H, PR:L and availability-only impact the practical attacker incentive is minimal.

Exploit ScenarioDerived

An authenticated OAuth2 client, with the allowed_scopes configuration enabled on an affected WSO2 deployment, introspects an access token and then immediately issues a revocation request for it. Because of the narrow timing window, the revoked token can be served again from the introspection cache until the cache entry expires, leaving the affected user temporarily unable to obtain a fresh valid token. No public exploit identified at time of analysis; realistic abuse is a self-inflicted or narrowly-timed denial of a new token rather than privilege escalation.

Monitor Track and reassess. Why: LOW severity (CVSS 0.1-3.9).
Patch available

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AnalysisAIv1 – Oct 28, 2026

Cached OAuth2 introspection responses in WSO2 API Manager, WSO2 Identity Server and related WSO2 identity/gateway products can cause a revoked access token to be returned to the client again until the cache entry is cleared, but only when the allowed_scopes configuration is enabled. An authenticated OAuth2 client able to call both the introspection and revocation endpoints must also hit a narrow ordering window - introspecting a token immediately before revoking it - which is why the issue is rated low (CVSS 3.1, AV:N/AC:H/PR:L, C:N/I:N/A:L). The re-issued token is not accepted for API authorization, so there is no confidentiality or integrity loss; the practical effect is a limited availability/authentication-flow disruption, since affected users may be unable to obtain a new valid token until the cache is flushed. No public exploit code and no active exploitation have been identified at time of analysis, and the priority decision is monitor.

RemediationAI

Apply the fix identified in WSO2 security advisory WSO2-2026-5175 (https://security.docs.wso2.com/en/latest/security-announcements/security-advisories/2026/WSO2-2026-5175/), which is the only vendor-referenced remediation source in the supplied data; exact fixed version numbers are not listed in this dataset, so confirm the target release for each deployed product (API Manager, Identity Server, Identity Server as Key Manager, Open Banking AM/IAM, Traffic Manager, Universal Gateway, API Control Plane) against that advisory before upgrading. Because the defect is gated on the allowed_scopes configuration, deployments that do not rely on scope restriction can disable that setting to remove the prerequisite, accepting the trade-off that allowed_scopes based scope enforcement is lost and must be replaced with equivalent authorization checks. As a supplementary operational measure, shortening or proactively flushing the introspection cache around revocation events reduces the exposure window, at the cost of additional introspection load on the authorization server. No public exploit code and no active exploitation are known at time of analysis, so this is a scheduled-maintenance item rather than an emergency change.

Affected VersionsENISA

WSO2 API Manager 4.1.0 <4.1.0.267
WSO2 Carbon OAuth 6.8.0 <6.8.0.59
WSO2 Identity Server as Key Manager 5.10.0 <5.10.0.387
WSO2 API Control Plane 4.6.0 <4.6.0.30
WSO2 Universal Gateway 4.6.0 <4.6.0.29
WSO2 Carbon OAuth 6.4.2 <6.4.2.178
WSO2 Carbon OAuth 6.4.176 <6.4.176.38
WSO2 Carbon OAuth 6.13.16 <6.13.16.32
WSO2 API Manager 4.2.0 <4.2.0.207
WSO2 Traffic Manager 4.7.0 <4.7.0.3
WSO2 API Manager 3.1.0 <3.1.0.367
WSO2 Carbon OAuth 7.0.26 <7.0.26.103
WSO2 Identity Server 7.2.0 <7.2.0.20
WSO2 Carbon OAuth 6.14.14 <6.14.14.3
WSO2 API Manager 3.2.1 <3.2.1.106
WSO2 Carbon OAuth 7.0.385 <7.0.385.15
WSO2 Identity Server 5.11.0 <5.11.0.444
WSO2 Open Banking AM 2.0.0 <2.0.0.414
WSO2 Open Banking IAM 2.0.0 <2.0.0.434
WSO2 API Manager 4.0.0 <4.0.0.394
WSO2 Identity Server 6.0.0 <6.0.0.270
WSO2 Carbon OAuth 7.4.99 <7.4.99.5
WSO2 Identity Server 7.0.0 <7.0.0.152
WSO2 API Manager 4.6.0 <4.6.0.29
WSO2 Traffic Manager 4.5.0 <4.5.0.65
WSO2 Carbon OAuth 6.11.21 <6.11.21.118
WSO2 Carbon OAuth 6.9.6 <6.9.6.36
WSO2 Carbon OAuth 6.4.111 <6.4.111.174
WSO2 Universal Gateway 4.5.0 <4.5.0.67
WSO2 API Manager 3.2.0 <3.2.0.475
WSO2 API Manager 4.5.0 <4.5.0.67
WSO2 API Manager 4.4.0 <4.4.0.83
WSO2 Identity Server 7.3.0 <7.3.0.1
WSO2 Universal Gateway 4.7.0 <4.7.0.3
WSO2 API Manager 4.7.0 <4.7.0.3
WSO2 Traffic Manager 4.6.0 <4.6.0.29
WSO2 Carbon OAuth 6.13.41 <6.13.41.9
WSO2 Identity Server 5.10.0 <5.10.0.397
WSO2 Carbon OAuth 6.13.19 <6.13.19.23
WSO2 Identity Server 6.1.0 <6.1.0.269
WSO2 Identity Server 7.1.0 <7.1.0.61
WSO2 Carbon OAuth 6.4.180 <6.4.180.25
WSO2 API Control Plane 4.5.0 <4.5.0.68
WSO2 Carbon OAuth 6.13.27 <6.13.27.21
WSO2 Carbon OAuth 7.0.259 <7.0.259.54
WSO2 API Manager 4.3.0 <4.3.0.120
WSO2 API Control Plane 4.7.0 <4.7.0.3

Affected Packages

euvd wso2_api_control_plane fix: 4.5.0.68, 4.6.0.30, 4.7.0.3
euvd wso2_api_manager fix: 3.1.0.367, 3.2.0.475, 3.2.1.106, 4.0.0.394, 4.1.0.267, 4.2.0.207, 4.3.0.120, 4.4.0.83, 4.5.0.67, 4.6.0.29, 4.7.0.3
euvd wso2_carbon_oauth fix: 6.4.2.178, 6.4.111.174, 6.4.176.38, 6.4.180.25, 6.8.0.59, 6.9.6.36, 6.11.21.118, 6.13.16.32, 6.13.19.23, 6.13.27.21, 6.13.41.9, 6.14.14.3, 7.0.26.103, 7.0.259.54, 7.0.385.15, 7.4.99.5
euvd wso2_identity_server fix: 5.10.0.397, 5.11.0.444, 6.0.0.270, 6.1.0.269, 7.0.0.152, 7.1.0.61, 7.2.0.20, 7.3.0.1
euvd wso2_identity_server_as_key_manager fix: 5.10.0.387
euvd wso2_open_banking_am fix: 2.0.0.414
euvd wso2_open_banking_iam fix: 2.0.0.434
euvd wso2_traffic_manager fix: 4.5.0.65, 4.6.0.29, 4.7.0.3
euvd wso2_universal_gateway fix: 4.5.0.67, 4.6.0.29, 4.7.0.3

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 9 packages in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The flaw sits in the OAuth2 token introspection and revocation handling of the WSO2 Carbon OAuth component (CWE-613, Insufficient Session Expiration). OAuth2 introspection (RFC 7662) lets a resource server ask the authorization server whether a token is active, and WSO2 caches those introspection responses for performance; OAuth2 revocation (RFC 7009) is the separate endpoint a client uses to invalidate a token. The reported behaviour is that a revocation request does not immediately evict the corresponding introspection cache entry, so a follow-up introspection that occurs before the entry expires can be answered from cache and hand the already-revoked token back to the client. The prerequisite named in the vendor advisory is the allowed_scopes configuration being enabled, so default deployments without that setting are outside the affected configuration. The trigger is a specific ordering condition - introspection immediately before revocation - reflected in the AC:H metric, and the attacker is a legitimate OAuth2 client (PR:L) rather than an anonymous party. Scope is deliberately limited: the re-issued token is not honoured for API authorization, there is no confidentiality or integrity impact (C:N/I:N), and the window closes as soon as the cache entry is cleared.

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Severity by source

Vendor (WSO2) PRIMARY 3.1 LOW
AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
vuln.today AI 3.1 LOW

Network-reachable introspection/revocation endpoints (AV:N) require valid client authentication (PR:L) and a narrow introspect-before-revoke ordering window (AC:H); only availability of new-token issuance is affected (A:L), with no confidentiality or integrity loss.

3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L
4.0 AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (WSO2).

CVSS VectorVendor: WSO2

Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

Lifecycle Timeline

1
Patch available
Oct 28, 2026 - 20:04 EUVD

DescriptionCVE.org

When the allowed_scopes configuration is enabled, the OAuth2 token introspection mechanism does not immediately invalidate a token in the cache after a revocation request. This results in a scenario where an access token that was introspected immediately before a revocation request may be returned again to the client after revocation, until the relevant cache entry is cleared.

The security consequence is that a revoked access token may be re-issued to the client during the cache lifetime. While the re-issued token is not treated as valid for API authorization, affected users may be unable to obtain a new valid access token until the cache is cleared, which can disrupt authentication flows.

Threat Intelligence Overview

Prevalence
Medium
widely-used enterprise API/identity platform, but not ubiquitous infrastructure
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity LOW
CISA KEV No
Public POC No
EPSS N/A
Patch available Yes
Active threat No
Deciding rule
LOW severity (CVSS 0.1-3.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Low

Priority Score

16
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +16
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

CVE-2026-5430 CRITICAL POC
10.0 Aug 06

Authentication bypass in WSO2 API Manager and related components (Universal Gateway, Traffic Manager, API Control Plane,

CVE-2026-2053 CRITICAL
10.0 Jun 26

Server-side request forgery in WSO2 API Manager lets unauthenticated remote attackers coerce the gateway into making ser

CVE-2026-1728 CRITICAL
9.8 Aug 06

Privilege escalation in WSO2 API Manager and related Carbon-based products allows a low-privileged user, using a validly

CVE-2025-15039 CRITICAL
9.4 Aug 06

Authentication bypass in WSO2 Identity Server and multiple WSO2 platform products (API Manager, Open Banking AM/IAM/KM,

CVE-2025-8325 HIGH
8.8 May 11

Missing role-based authorization on WSO2 API Manager's Gateway REST API lets any authenticated user invoke privileged Ga

CVE-2026-4249 HIGH
8.6 Jul 06

Persistent denial of service in multiple WSO2 products - including WSO2 API Manager, WSO2 Universal Gateway, WSO2 Traffi

CVE-2025-12737 HIGH
8.4 Sep 03

OS command injection (CWE-78) in WSO2's shared Carbon Console administrative interface allows an authenticated administr

CVE-2025-14260 HIGH
8.3 Oct 28

Server-side request forgery in WSO2 API Manager and related WSO2 products lets a remote attacker direct the server to ar

CVE-2026-3416 HIGH
7.5 Sep 03

Predictable HMAC shared secrets generated by the API Publisher component of WSO2 API Manager allow a sophisticated attac

CVE-2025-8154 HIGH
7.5 May 11

HTTP response header injection in WSO2 API Manager and its companion WSO2 gateway components (Universal Gateway, Traffic

CVE-2024-2374 HIGH
7.5 Apr 16

The XML parsers within multiple WSO2 products accept user-supplied XML data without properly configuring to prevent the

CVE-2025-13173 MEDIUM
6.5 Oct 19

WSO2 Carbon OAuth, as shipped in WSO2 Identity Server, API Manager, and related WSO2 products, can leave session-bound t

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