# CVE-2026-114138: Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 21 Oct 2026
- **Updated:** 28 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-114138, ECHO-0cda-00c4-9b00, GHSA-33wh-fxxf-88vv, ROOT-APP-PYPI-CVE-2026-114138, UBUNTU-CVE-2026-114138

## What is CVE-2026-114138?

CVE-2026-114138 is a high-severity vulnerability in encode django-rest-framework, published on 21 Oct 2026. 

### Official description

Django REST framework is a toolkit for building Web APIs. Prior to 3.18.2, DefaultContentNegotiation.get_accept_list in rest_framework/negotiation.py accepts an unbounded number and aggregate size of Accept tokens, while select_renderer in that file repeatedly invokes _MediaType parsing from rest_framework/utils/mediatypes.py for each attacker-controlled token, every renderer, and forced 406 renegotiation. A remote unauthenticated client can send many distinct media types containing large quoted parameter values with numerous semicolons, causing Django's parameter parser and DRF's repeated parsing structure to consume disproportionate CPU. Requests to any reachable endpoint can pin synchronous workers for prolonged periods, and concurrent requests can make the service unavailable until the requests stop. This issue is fixed in version 3.18.2.

Weakness: CWE-407 (Inefficient Algorithmic Complexity), CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2026-114138?

2 open source packages ship an affected version, including djangorestframework.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `djangorestframework` | PyPI | All versions | 3.18.2 |
| `djangorestframework` | PyPI | All versions | 3.18.2 |

## How do I fix CVE-2026-114138?

Upgrade djangorestframework to 3.18.2 or later.

## Is CVE-2026-114138 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-114138 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-114138 and fix it if it is affected.

What it is: CVE-2026-114138 is a high-severity vulnerability in encode django-rest-framework, published on 21 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-114138 exists.

Affected packages and fixed versions:
- djangorestframework (PyPI): affected all versions; fixed in 3.18.2
- djangorestframework (PyPI): affected all versions; fixed in 3.18.2

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-2026-114138/ (Markdown: https://insights.sbomify.com/CVE-2026-114138/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-114138
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-114138
- OSV: https://osv.dev/vulnerability/CVE-2026-114138

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-114138/
Summaries are generated and may contain mistakes; the official description above is the record.