CVE-2026-114138 — Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+7
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Pip Djangorestframework: fixed in version 3.18.2 — github.com (GitHub Security Advisories)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Encode Django-rest-framework, Pip Djangorestframework).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Encode | Django-rest-framework | version < 3.18.2 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Pip | Djangorestframework | < 3.18.2 | Vulnerable | GitHub Security Advisories |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | security-advisories@github.com via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.5 | CVSS 3.1 | High | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 22, 2026 → Oct 27, 2026 · 6 reading(s) · max 0.52%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · pip/djangorestframework
- Source status changed · Received → Awaiting Analysis
- Source status changed · Published → Received
- Record published
- Affected products added · encode/django-rest-framework
- CVSS changed · 7.5
- Source status changed · → Published
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 21, 2026 – Oct 22, 2026
- 1× Official description updated · Oct 21, 2026 – Oct 21, 2026
References
5 on the record
- github.com/encode/django-rest-framework/releases/tag/3.18.2
- github.com/encode/django-rest-framework/security/advisories/GHSA-33wh-fxxf-88vv
- github.com/encode/django-rest-framework/commit/148ab6523922d5a0c110f76615935e522
- github.com/advisories/GHSA-33wh-fxxf-88vv
- nvd.nist.gov/vuln/detail/CVE-2026-114138
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-114137 Django REST framework: TokenProxy.delete() reports success and revokes nothing 6d
- High CVE-2026-114136 Django REST framework: JSONParser applies an attacker-named codec to the request stream 6d
- Medium CVE-2026-73229 Django REST framework: AdminRenderer may disclose GET-protected data when rendering invalid write requests Aug 11, 2026
- Medium CVE-2026-73228 Django REST framework: Potential bypass of Django `DATA_UPLOAD_MAX_MEMORY_SIZE` when parsing oversized JSON and urlencoded request bodies via DRF `request.data` Aug 11, 2026
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-114138 is "Django REST framework: Accept header with many large quoted parameters burns ~19s of CPU per request in content negotiation", rated High. It affects Django-rest-framework (Encode); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. EPSS 0.52% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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