# CVE-2026-100667: grav-plugin-login 3.8.7 through 3.9.6 Two-Factor Authentication Bypass

> Attackers with valid passwords can bypass two-factor authentication to read member-only content in Grav CMS.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-r29m-xqx4-rwgf

## What is CVE-2026-100667?

CVE-2026-100667 is a medium-severity authentication bypass vulnerability in getgrav grav, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

grav-plugin-login (the Grav CMS Login plugin) versions >= 3.8.7 and < 3.9.7 allow the two-factor authentication challenge to be bypassed for content gated by the authenticated() Twig function or the [authenticated] shortcode. On sites with 2FA enabled, Login::isAuthenticated() checked only the session flag indicating that the password step had succeeded, not the flag indicating that login had completed, so a session sitting at the 2FA code prompt was treated as fully authenticated. An attacker who knows a member's password but cannot answer that member's second factor can therefore read member-only content rendered by the no-argument authenticated() or group authenticated(null, 'group') forms and by [authenticated]; the inverse [guest] shortcode is likewise evaluated too early. Impact is limited to disclosure of that content: the attacker does not obtain a completed session, cannot access pages protected by an access: rule, and cannot act as the user. The authenticated('some.permission') form, which goes through UserObject::authorize(), is not affected. Fixed in grav-plugin-login 3.9.7.

Weakness: CWE-304 (Missing Critical Step in Authentication)

## Which versions are affected by CVE-2026-100667?


## How do I fix CVE-2026-100667?

No fix has been published for CVE-2026-100667 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100667 being exploited?

There is no known exploitation of CVE-2026-100667 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100667 and fix it if it is affected.

What it is: CVE-2026-100667 is a medium-severity authentication bypass vulnerability in getgrav grav, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-100667 in the wild and no public exploit code.

Affected product: getgrav grav. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-100667/ (Markdown: https://insights.sbomify.com/CVE-2026-100667/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100667
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100667
- OSV: https://osv.dev/vulnerability/CVE-2026-100667

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100667/
Summaries are generated and may contain mistakes; the official description above is the record.