Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Affected: python-multipart versions before 0.0.31. A negative Content-Length value passed to parse_form() causes the whole request body to be read into memory at once instead of in chunks. The attack needs only to send a crafted request, and the impact is limited to applications that call parse_form() directly with raw client headers, where it can degrade availability under concurrent requests. Upgrade to python-multipart 0.0.31 or later, which rejects negative Content-Length values.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 3.7 | Low | 3.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0034, the 27th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:29 UTC First seen by agentprime
- 31 Oct 2026, 14:29 UTC Confirmed by OSV