# CVE-2026-88007: Traefik HTTP/3 Backend NTLM Connection Reuse

> Attackers can reuse authenticated backend connections to read victim data and act as victims when HTTP/3 and NTLM are enabled.

- **Severity:** Critical 9.1 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/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:** Yes
- **Published:** 10 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** ECHO-22a3-b491-e65f, GHSA-qqjf-53cj-pwvv, GO-2026-6466, MINI-hphg-p675-wx3f, MINI-m2m3-mg8r-647g, MINI-x878-xwv5-8x62

## What is CVE-2026-88007?

CVE-2026-88007 is a critical authentication bypass vulnerability in Traefik Traefik, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection. With HTTP/3 enabled, a backend using connection-bound NTLM or Negotiate authentication, and backend keep-alive, an unrelated client can reuse a backend connection authenticated for a victim, read victim-only data, and act as that victim without the victim credentials. This issue is fixed in 2.11.57 and 3.7.13.

Weakness: CWE-863 (Incorrect Authorization), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-88007?

7 open source packages ship an affected version, including github.com/traefik/traefik/v2, github.com/traefik/traefik and github.com/traefik/traefik/v3. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/traefik/traefik/v2` | Go | From 2.11.0 | 2.11.57 |
| `github.com/traefik/traefik/v2` | Go | From 2.11.0 | 2.11.57 |
| `github.com/traefik/traefik/v2` | Go | From 2.11.0 | 2.11.57 |
| `github.com/traefik/traefik` | Go | All versions | None |
| `github.com/traefik/traefik/v3` | Go | From 3.0.0 | 3.7.13 |
| `github.com/traefik/traefik/v3` | Go | From 3.0.0 | 3.7.13 |
| `github.com/traefik/traefik/v3` | Go | From 3.0.0 | 3.7.13 |

Products: Traefik Traefik.

## How do I fix CVE-2026-88007?

Upgrade github.com/traefik/traefik/v2 to 2.11.57 or later.

## Is CVE-2026-88007 being exploited?

There is no known exploitation of CVE-2026-88007 in the wild and no public exploit code.

## Other vulnerabilities in Traefik Traefik

- [CVE-2024-45410](https://insights.sbomify.com/CVE-2024-45410/): HTTP client can remove the X-Forwarded headers in Traefik (critical 9.8)
- [CVE-2026-88877](https://insights.sbomify.com/CVE-2026-88877/): Traefik v3.7.0 Authentication Bypass via from-to-www-redirect (critical 9.3)
- [CVE-2026-85595](https://insights.sbomify.com/CVE-2026-85595/): Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth (critical 9.3)
- [CVE-2026-88009](https://insights.sbomify.com/CVE-2026-88009/): Traefik: Rootless HTTP/1 request-target routes as "/" but is forwarded verbatim, bypassing path-scoped routing, middleware guards and access logging (high 8.8)
- [CVE-2025-32431](https://insights.sbomify.com/CVE-2025-32431/): Traefik has a possible vulnerability with the path matchers (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88007 and fix it if it is affected.

What it is: CVE-2026-88007 is a critical authentication bypass vulnerability in Traefik Traefik, published on 10 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-2026-88007 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/traefik/traefik/v2 (Go): affected from 2.11.0; fixed in 2.11.57
- github.com/traefik/traefik/v2 (Go): affected from 2.11.0; fixed in 2.11.57
- github.com/traefik/traefik/v2 (Go): affected from 2.11.0; fixed in 2.11.57
- github.com/traefik/traefik (Go): affected all versions; no fix listed
- github.com/traefik/traefik/v3 (Go): affected from 3.0.0; fixed in 3.7.13
- github.com/traefik/traefik/v3 (Go): affected from 3.0.0; fixed in 3.7.13
- github.com/traefik/traefik/v3 (Go): affected from 3.0.0; fixed in 3.7.13

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-2026-88007/ (Markdown: https://insights.sbomify.com/CVE-2026-88007/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88007
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88007
- OSV: https://osv.dev/vulnerability/CVE-2026-88007

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88007/
Summaries are generated and may contain mistakes; the official description above is the record.