CVE-2026-114138 Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation
- Exploited in the wild
- Not known
- Fix
- Available
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.
Which versions are affected by CVE-2026-114138?
2 open source packages ship an affected version, including djangorestframework.
| Package | 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.
Sources
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.