# CVE-2026-55167: LDAP Account Manager: WebAuthn authentication challenge is kept in the PHP session

> Attackers with valid credentials and session access can reuse WebAuthn challenges, bypassing two-factor authentication requirements in LDAP Account Manager.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-55167, GHSA-xgjg-fchx-x3g3, UBUNTU-CVE-2026-55167

## What is CVE-2026-55167?

CVE-2026-55167 is a medium-severity vulnerability in LDAPAccountManager lam, published on 14 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

LDAP Account Manager (LAM) is a webfrontend for managing entries (e.g. users, groups, DHCP settings) stored in an LDAP directory. Prior to 9.6, installations with WebAuthn two-factor authentication leave the challenge in the same PHP session after the authentication response is processed. A user who has already completed valid password authentication can therefore retain the same signed WebAuthn ceremony state instead of consuming it once. The practical risk is limited by the requirement for a valid password, the same PHP session, and a valid authenticator signature. This issue is fixed in version 9.6.

Weakness: CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2026-55167?


## How do I fix CVE-2026-55167?

Upgrade to a fixed version.

## Is CVE-2026-55167 being exploited?

There is no known exploitation of CVE-2026-55167 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55167 and fix it if it is affected.

What it is: CVE-2026-55167 is a medium-severity vulnerability in LDAPAccountManager lam, published on 14 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55167 in the wild and no public exploit code.

Affected product: LDAPAccountManager lam. 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-2026-55167/ (Markdown: https://insights.sbomify.com/CVE-2026-55167/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55167
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55167
- OSV: https://osv.dev/vulnerability/CVE-2026-55167

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55167/
Summaries are generated and may contain mistakes; the official description above is the record.