VulnerabilityPublished 9 Nov 2026

CVE-2026-62662: Pocket ID · The client credentials grant allows any OIDC client to obtain tokens for arbitrary audiences

Affects github.com/pocket-id/pocket-id/backendSource GCVE Database

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Authoritative record:CVE-2026-62662· High 7.7

Not known to be exploited · CVSS 7.7 High : upgrade to 0.0.0-20260622164202-8158452b3730 soon.

Data as of 9 Nov 2026, 23:24 UTC

CVSS 3.0 base score

7.7High

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.0	7.7

EPSS: 0.2% chance of exploitation in 30 days – higher than 18% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.0.0-20260622164202-8158452b3730

CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: High
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade github.com/pocket-id/pocket-id/backend to 0.0.0-20260622164202-8158452b3730.

Affected software

Product	Affected	Fixed in
Gogithub.com/pocket-id/pocket-id/backend	Affected <0.0.0-20260622164202-8158452b3730	Fixed in 0.0.0-20260622164202-8158452b3730

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

## Summary The client credentials grant (`grant_type=client_credentials`) does not validate the resource parameter before embedding it as the aud claim in the issued JWT. Any authenticated OIDC client can obtain a Pocket ID-signed access token claiming authorization for any arbitrary audience, including other registered OIDC clients. There is no check that the requested audience is a registered resource server, and no check that the requesting client has been granted permission to access it. ## Details In `backend/internal/service/oidc_service.go`, `createTokenFromClientCredentials` accepts the resource parameter from the token request and places it directly into the `aud` claim of the issued JWT without validation: ```golang audClaim := client.ID if input.Resource != "" { audClaim = input.Resource // no validation performed } accessToken, err := s.jwtService.GenerateOAuthAccessToken(dummyUser, audClaim) ``` The only guard in this function is `verifyClientCredentialsInternal`, which confirms the requesting client's credentials are valid. After that check passes, any value supplied as resource is accepted. There is no registry of permitted audiences, no per-client authorization policy controlling which resources a client may request tokens for, and no validation that the resource value corresponds to anything registered in Pocket ID. The introspection endpoint (`/api/oidc/introspect`) does not mitigate this. It checks that the introspecting client's ID matches the token's `aud` claim, but since the attacker controls `aud`, a resource server calling introspection to validate an inbound token will receive `"active": true`. Pocket ID has no server-side record of which client requested the token or whether it was authorized to do so, so introspection cannot distinguish a legitimately issued token from one obtained through this vulnerability. ## PoC Given a Pocket ID instance with two registered OIDC clients — `client-a` (attacker-controlled) and `client-b` (target resource) — the following request causes Pocket ID to issue a signed JWT with `aud: ["client-b"]`, authenticated only as `client-a`: ``` curl -X POST https://<pocket-id-host>/api/oidc/token \ -d "grant_type=client_credentials" \ -d "client_id=client-a" \ -d "client_secret=<client-a-secret>" \ -d "resource=client-b" ``` The response is a valid, Pocket ID-signed JWT with: ```json { "sub": "client-client-a", "aud": ["client-b"], "iss": "https://<pocket-id-host>", "type": "oauth-access-token" } ``` This token will pass signature and `aud` validation at any resource server that trusts Pocket ID's JWKS and accepts `client-b` as its audience identifier. ## Impact Any OIDC client registered in Pocket ID that has valid credentials (client secret or federated identity) can obtain a Pocket ID-signed access token scoped to any other registered client or arbitrary audience string. In deployments where services use the client credentials grant and validate incoming bearer tokens against Pocket ID's JWKS, this allows a compromised or malicious client to bypass audience-based access controls and present tokens to resource servers it should not be authorized to access. The severity depends on deployment: if no resource servers validate Pocket ID-issued access tokens, there is no immediate exploitable impact. In deployments that do rely on the client credentials grant for service-to-service authorization, the isolation between services is entirely broken.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Affected software

Description

WeaknessesCWE-20, CWE-863

Technical details

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