CVE-2026-40347
Description
Python-Multipart is a streaming multipart parser for Python. Versions prior to 0.0.26 have a denial of service vulnerability when parsing crafted `multipart/form-data` requests with large preamble or epilogue sections. Upgrade to version 0.0.26 or later, which skips ahead to the next boundary candidate when processing leading CR/LF data and immediately discards epilogue data after the closing boundary.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 0.0.26-1 |
| forky | Fixed | 0.0.26-1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | python-multipart | <0.0.26 | 0.0.26 |
References
- https://github.com/Kludex/python-multipart/security/advisories/GHSA-mj87-hwqh-73pj
- https://nvd.nist.gov/vuln/detail/CVE-2026-40347
- https://github.com/Kludex/python-multipart
- https://github.com/Kludex/python-multipart/releases/tag/0.0.26
- https://www.suse.com/security/cve/CVE-2026-40347.html
- https://security-tracker.debian.org/tracker/CVE-2026-40347
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.