# CVE-2026-73812: inets, httpd: HTTP Request Smuggling via Transfer-Encoding and Content-Length

> Attackers can exploit HTTP request smuggling in Erlang OTP inets by sending conflicting Transfer-Encoding and Content-Length headers, bypassing front-end security controls.

- **Severity:** High 8.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/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:** 1 Sep 2026
- **Updated:** 8 Sep 2026
- **Also known as:** AZL-98490, DEBIAN-CVE-2026-73812, EEF-CVE-2026-73812, GHSA-7j6m-4ffg-hg46, UBUNTU-CVE-2026-73812

## What is CVE-2026-73812?

CVE-2026-73812 is a high-severity vulnerability in Erlang OTP, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

httpd function check_header/3 rejects duplicate Content-Length (per CVE-2026-23941) but never checks for the TE+CL co-presence that RFC 9112 §6.3 identifies as a probable smuggling attempt. handle_body/3 frames by chunked and silently discards Content-Length. A CL-preferring front-end paired with chunked-preferring inets creates a classic CL.TE front-end/back-end desync.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 before OTP 29.0.6, corresponding to inets from 5.10 before 9.3.2.7, from 9.4 before 9.6.2.3, and from 9.7 before 9.7.2. Whether OTP before OTP 17.0, corresponding to inets before 5.10, is affected is unknown.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2026-73812?


## How do I fix CVE-2026-73812?

Upgrade to a fixed version.

## Is CVE-2026-73812 being exploited?

There is no known exploitation of CVE-2026-73812 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-73812 and fix it if it is affected.

What it is: CVE-2026-73812 is a high-severity vulnerability in Erlang OTP, published on 1 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-2026-73812 in the wild and no public exploit code.

Affected product: Erlang OTP. 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-2026-73812/ (Markdown: https://insights.sbomify.com/CVE-2026-73812/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-73812
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-73812
- OSV: https://osv.dev/vulnerability/CVE-2026-73812

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-73812/
Summaries are generated and may contain mistakes; the official description above is the record.