# CVE-2026-58488: HedgeDoc: Rate-limit bypass via CF-Connecting-IP header spoofing

> Attackers can bypass rate limits on login and registration by spoofing the CF-Connecting-IP header, enabling spam and account creation.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:** 13 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-2f9f-w8xq-276v

## What is CVE-2026-58488?

CVE-2026-58488 is a medium-severity vulnerability in hedgedoc, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

HedgeDoc is an open source, real-time, collaborative, markdown notes application. Versions prior to 1.11.0 allowed attackers to circumvent the rate-limiting of the /login and /register routes by spoofing IP addresses. HedgeDoc instances checked for CloudFlare's cf-connecting-ip header and used that instead of the users real IP address, if the header was present even when the request did not originate from Cloudflare. This made it possible for an attacker to spam login requests or create multiple arbitrary accounts by sending another cf-connecting-ip header every few requests. The issue has been fixed in version 1.11.0.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-58488?


## How do I fix CVE-2026-58488?

No fix has been published for CVE-2026-58488 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-58488 being exploited?

There is no known exploitation of CVE-2026-58488 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58488 and fix it if it is affected.

What it is: CVE-2026-58488 is a medium-severity vulnerability in hedgedoc, published on 13 Jul 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-2026-58488 in the wild and no public exploit code.

Affected product: hedgedoc. 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-2026-58488/ (Markdown: https://insights.sbomify.com/CVE-2026-58488/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58488
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58488
- OSV: https://osv.dev/vulnerability/CVE-2026-58488

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58488/
Summaries are generated and may contain mistakes; the official description above is the record.