How severe is CVE-2021-29652?

CVE-2021-29652 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-29652?

CVE-2021-29652 affects the following packages: github.com/pomerium/pomerium (Go). Ecosystems affected: Go.

How do I fix CVE-2021-29652?

Update github.com/pomerium/pomerium to 0.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29652 is resolved across your whole dependency graph.

How do I detect CVE-2021-29652 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/pomerium/pomerium, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-29652 if there is no patch (or I can't update yet)?

Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Is CVE-2021-29652 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-29652 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-29652?

CVE-2021-29652 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 50th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-29652?

CVE-2021-29652 is classified as Open Redirect (CWE-601). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-29652 published, and has it been updated?

CVE-2021-29652 was published on April 2, 2021 and was last updated on July 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

MEDIUM severity

CVE-2021-29652 — pomerium

MEDIUMFix: pomerium/pomerium#2048

CVE-2021-29652 is a medium-severity (CVSS 6.1) Open Redirect vulnerability in github.com/pomerium/pomerium. A fix is available for github.com/pomerium/pomerium — see the affected versions and patch details below.

pomerium_signature is not verified in middleware in github.com/pomerium/pomerium

Also known asGHSA-fv82-r8qv-ch4vGO-2022-0827

Published

Apr 2, 2021

Updated

Jul 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs50th percentile — riskier than 50% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-29652 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

🐹github.com/pomerium/pomerium

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Impact

Some API endpoints under /.pomerium/ do not verify parameters with pomerium_signature. This could allow modifying parameters intended to be trusted to Pomerium.

The issue mainly affects routes responsible for sign in/out, but does not introduce an authentication bypass.

Specific Go Packages Affected

github.com/pomerium/pomerium/authenticate

Patches

Patched in v0.13.4

For more information

If you have any questions or comments about this advisory

Open an issue in pomerium
Email us at [email protected]

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/pomerium/pomerium`	≥ 0.10.0&&< 0.13.4	0.13.4`go get github.com/pomerium/pomerium@v0.13.4`

Affected Products

1 product · 1 configurations

Application

pomeriumpomerium

≥ 0.10.0 && ≤ 0.13.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/pomerium/pomerium, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/pomerium/pomerium to 0.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-29652 is resolved across your whole dependency graph.
Workarounds
Stop reflecting attacker-controlled destinations: resolve every redirect target against an allowlist of paths or hosts you own, prefer a server-side key over a full URL in the request, and reject absolute URLs entirely where the flow only ever needs a relative one.

Frequently Asked Questions

### Impact Some API endpoints under /.pomerium/ do not verify parameters with pomerium_signature. This could allow modifying parameters intended to be trusted to Pomerium. The issue mainly affects routes responsible for sign in/out, but does not introduce an authentication bypass. ### Specific Go Packages Affected github.com/pomerium/pomerium/authenticate ### Patches Patched in v0.13.4 ### For more information If you have any questions or comments about this advisory * Open an issue in [pomerium](http://github.com/pomerium/pomerium) * Email us at [[email protected]](mailto:security@po

O3 Security · Impact-Aware SCA

Is CVE-2021-29652 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-601Open Redirect

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

pomerium

7.0/10

Code-Review10/10

Maintained10/10

Branch-ProtectionN/A

Assessed Oct 5, 2026

Timeline

Disclosed

Apr 2, 2021

Last updated

Jul 9, 2026

Identifiers

CVE-2021-29652

GHSA-fv82-r8qv-ch4v

GO-2022-0827

References

Advisorygithub.com Advisorynvd.nist.gov Webgithub.com

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs affecting pomerium are rated as high or higher (top: critical).

CVE-2026-50285CVE-2024-47616CVE-2022-24797CVE-2024-39315CVE-2023-33189GHSA-j34v-3552-5r7jCVE-2021-41230CVE-2021-39204

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 9, 2026