# CVE-2026-68555: coturn: Chained mobility resumes allow authenticated remote memory exhaustion

> An authenticated attacker can exhaust server memory by repeatedly resuming allocations when mobility is enabled, causing denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 19 Aug 2026
- **Updated:** 21 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-68555, GHSA-hpq3-g7x4-h7xx, MINI-rxrh-75f6-vpjh, UBUNTU-CVE-2026-68555

## What is CVE-2026-68555?

CVE-2026-68555 is a medium-severity denial of service vulnerability in coturn, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Coturn is a free open source implementation of TURN and STUN Server. In 4.15.0, an authenticated TURN user can repeatedly resume one allocation from fresh UDP 5-tuples without completing a handoff when the server enables --mobility. mobile_begin_transition() in src/server/ns_turn_server.c disarms each new session's allocation timeout and overwrites the allocation's single mobile_pending_resume link, leaving earlier pending sessions unreachable by the cleanup path, while copy_auth_parameters() ignores inc_quota() failure. The attacker can therefore retain unbounded server-side sessions and exhaust process memory even when --user-quota=1 is configured. This issue is fixed in version 4.16.0.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-68555?


## How do I fix CVE-2026-68555?

Upgrade to a fixed version.

## Is CVE-2026-68555 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68555 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68555 and fix it if it is affected.

What it is: CVE-2026-68555 is a medium-severity denial of service vulnerability in coturn, published on 19 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68555 exists.

Affected product: coturn. 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-2026-68555/ (Markdown: https://insights.sbomify.com/CVE-2026-68555/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68555
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68555
- OSV: https://osv.dev/vulnerability/CVE-2026-68555

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68555/
Summaries are generated and may contain mistakes; the official description above is the record.