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HIGH severity

CVE-2024-27918 — coder

HIGHFix: coder/coder@1171ce7

CVE-2024-27918 is a high-severity (CVSS 8.2) Improper Input Validation vulnerability in github.com/coder/coder/v2. A fix is available for github.com/coder/coder/v2 — see the affected versions and patch details below.

Coder's OIDC authentication allows email with partially matching domain to register

Also known asGHSA-7cc2-r658-7xpfGO-2024-2602
Published
Updated
Affected
4 pkgs
Patched
3 / 4
Exploits
None indexed
Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-27918.

EPSS Exploitation Probability

via FIRST.org ↗
1.0%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs62th percentile — riskier than 62% of all scored CVEsHighest risk
0.00%0.49%0.98%1.47%0.2%1.0%May 26Sep 26Nov 26

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 pkgs affected
🐹github.com/coder/coder/v2🐹github.com/coder/coder/v2🐹github.com/coder/coder/v2🐹github.com/coder/coder

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

Summary

A vulnerability in Coder's OIDC authentication could allow an attacker to bypass the CODER_OIDC_EMAIL_DOMAIN verification and create an account with an email not in the allowlist. Deployments are only affected if the OIDC provider allows users to create accounts on the provider (such as public providers like google.com).

Details

During OIDC registration, the user's email was improperly validated against the allowed CODER_OIDC_EMAIL_DOMAINs. This could allow a user with a domain that only partially matched an allowed domain to successfully login or register (e.g. [email protected] would match the allowed domain corp.com).

An attacker could register a domain name that exploited this vulnerability and register on a Coder instance with a public OIDC provider.

Impact

Coder instances with OIDC enabled and protected by the CODER_OIDC_EMAIL_DOMAIN configuration.

Coder instances using a private OIDC provider are not affected, as arbitrary users cannot register through a private OIDC provider without first having an account on the provider.

Public OIDC providers (such as google.com without permitted domains set on the OAuth2 App) are impacted.

GitHub authentication and external authentication are not impacted.

Was my deployment impacted?

To check if your deployment was exploited:

  • View the audit log on your deployment for unexpected registered users (using the action:register filter)
  • Check the users list for unexpected users
    • Users created via this exploit will have a domain that ends with one of the allowed domains but doesn’t fully match (e.g. @exploitcorp.com instead of @corp.com)

Patched Versions

This vulnerability is remedied in

  • v2.8.4
  • v2.7.3
  • v2.6.1

All versions prior to these patches are affected by the vulnerability. It is recommended that customers upgrade their deployments as soon as possible if they are utilizing OIDC authentication with the CODER_OIDC_EMAIL_DOMAIN setting.

Thanks

References

https://github.com/coder/coder/security/advisories/GHSA-7cc2-r658-7xpf https://github.com/coder/coder/commit/4439a920e454a82565e445e4376c669e3b89591c https://nvd.nist.gov/vuln/detail/CVE-2024-27918

Affected Packages

4 total 3 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/coder/coder/v2≥ 2.8.0&&< 2.8.42.8.4go get github.com/coder/coder/v2@v2.8.4
🐹Gogithub.com/coder/coder/v2≥ 2.7.0&&< 2.7.32.7.3go get github.com/coder/coder/v2@v2.7.3
🐹Gogithub.com/coder/coder/v2all versions2.6.1go get github.com/coder/coder/v2@v2.6.1
🐹Gogithub.com/coder/coderall versionsNo fix

Affected Products

1 product · 3 configurations
Application
codercoder
≥ 2.8.0 && < 2.8.4
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/coder/coder/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update github.com/coder/coder/v2 to 2.8.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-27918 is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

### Summary A vulnerability in Coder's OIDC authentication could allow an attacker to bypass the `CODER_OIDC_EMAIL_DOMAIN` verification and create an account with an email not in the allowlist. Deployments are only affected if the OIDC provider allows users to create accounts on the provider (such as public providers like `google.com`). ### Details During OIDC registration, the user's email was improperly validated against the allowed `CODER_OIDC_EMAIL_DOMAIN`s. This could allow a user with a domain that only partially matched an allowed domain to successfully login or register (e.g. `user@ex
O3 Security · Impact-Aware SCA

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CVE-2024-27918: coder — Fixed in 2.8.4