CVE-2024-39315
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response
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.
- Record
CVE-2024-39315- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
EUVDEUVD-2024-2413
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.
- Record
EUVD-2024-2413- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-rrqr-7w59-637v
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response
Impact
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 an XSS 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.
Patches
Patched in Pomerium v0.26.1.
Workarounds
None
For more information
If you have any questions or comments about this advisory:
- Open an issue in pomerium/pomerium
- Email us at [email protected]
Credit to Vadim Sheydaev, aka Enr1g for reporting this issue.
- Record
GHSA-rrqr-7w59-637v- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2024-39315- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
OSV
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response
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.
- Record
CVE-2024-39315- CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
OSVGHSA-rrqr-7w59-637v
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response
Impact
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 an XSS 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.
Patches
Patched in Pomerium v0.26.1.
Workarounds
None
For more information
If you have any questions or comments about this advisory:
- Open an issue in pomerium/pomerium
- Email us at [email protected]
Credit to Vadim Sheydaev, aka Enr1g for reporting this issue.
- Record
GHSA-rrqr-7w59-637v- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 5.7 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N - Weakness
- CWE-201
- Updated
- 2026-11-02
OSVGO-2024-2965 No score
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response in github.com/pomerium/pomerium
Pomerium exposed OAuth2 access and ID tokens in user info endpoint response in github.com/pomerium/pomerium
- Record
GO-2024-2965- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/pomerium/pomeriumGo |
before 0.26.1 | 0.26.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-39315 is a medium vulnerability (CVSS 5.7) in Pomerium, published July 2, 2024. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.42%, the 36th percentile. Fixed in github.com/pomerium/pomerium 0.26.1.
References
github.com/pomerium/pomerium/security/advisories/GHSA-rrqr-7w59-637v
nvd.nist.gov/vuln/detail/CVE-2024-39315