Pomerium

Pomerium is an identity and context-aware access proxy. Prior to 0.32.8, decodeQueryStringV2 in pkg/hpke/url.go performs zstd decompression of attacker-controlled data without an output-memory limit when DecryptURLValues processes HPKE V2 values for Stateless.Callback in internal/authenticateflow/stateless.go. In hosted or stateless authentication deployments, an unauthenticated attacker can obtain the receiver key from /.well-known/pomerium/hpke-public-key, provide a matching attacker-controlled sender key, and send a compressed payload to /.pomerium/callback that expands before validateSenderPublicKey rejects the sender. This can allocate hundreds of megabytes per request, exhaust proxy memory, crash or degrade the process, and block access to applications protected by the deployment. Stateful deployments are not affected because the stateful callback verifies its HMAC signature before decryption and decompression. This issue is fixed in version 0.32.8.

Published: 2026-09-17T19:49:20.917Z
Updated: 2026-09-17T20:19:48.967Z

Pomerium is an identity and context-aware access proxy. The Pomerium databroker service is responsible for managing all persistent Pomerium application state. Requests to the databroker service API are authorized by the presence of a JSON Web Token (JWT) signed by a key known by all Pomerium services in the same deployment. However, incomplete validation of this JWT meant that some service account access tokens would incorrectly be treated as valid for the purpose of databroker API authorization. Improper access to the databroker API could allow exfiltration of user info, spoofing of user sessions, or tampering with Pomerium routes, policies, and other settings. A Pomerium deployment is susceptible to this issue if all of the following conditions are met, you have issued a service account access token using Pomerium Zero or Pomerium Enterprise, the access token has an explicit expiration date in the future, and the core Pomerium databroker gRPC API is not otherwise secured by network access controls. This vulnerability is fixed in 0.27.1.

Published: 2024-10-02T21:10:24.146Z
Updated: 2024-10-03T15:43:26.879Z

Pomerium is an identity and context-aware access proxy. Prior to version 0.26.1, the Pomerium user info page (at `/.pomerium`) unintentionally included serialized OAuth2 access and ID tokens from the logged-in user's session. These tokens are not intended to be exposed to end users. This issue may be more severe in the presence of a cross-site scripting vulnerability in an upstream application proxied through Pomerium. If an attacker could insert a malicious script onto a web page proxied through Pomerium, that script could access these tokens by making a request to the `/.pomerium` endpoint. Upstream applications that authenticate only the ID token may be vulnerable to user impersonation using a token obtained in this manner. Note that an OAuth2 access token or ID token by itself is not sufficient to hijack a user's Pomerium session. Upstream applications should not be vulnerable to user impersonation via these tokens provided the application verifies the Pomerium JWT for each request, the connection between Pomerium and the application is secured by mTLS, or the connection between Pomerium and the application is otherwise secured at the network layer. The issue is patched in Pomerium v0.26.1. No known workarounds are available.

Published: 2024-07-02T20:02:06.120Z
Updated: 2024-08-02T04:19:20.747Z

Pomerium is an identity and context-aware access proxy. With specially crafted requests, incorrect authorization decisions may be made by Pomerium. This issue has been patched in versions 0.17.4, 0.18.1, 0.19.2, 0.20.1, 0.21.4 and 0.22.2.

Published: 2023-05-30T05:39:45.132Z
Updated: 2025-01-10T19:02:02.336Z

Pomerium is an identity-aware access proxy. In distributed service mode, Pomerium's Authenticate service exposes pprof debug and prometheus metrics handlers to untrusted traffic. This can leak potentially sensitive environmental information or lead to limited denial of service conditions. This issue is patched in version v0.17.1 Workarounds: Block access to `/debug` and `/metrics` paths on the authenticate service. This can be done with any L7 proxy, including Pomerium's own proxy service.

Published: 2022-03-31T22:40:12.000Z
Updated: 2025-04-23T18:42:56.245Z