---
id: "CVE-2026-103995"
kind: "vulnerability"
aliases: ["CVE-2026-103995"]
title: "Python: lenient integer parsing misreads HTTP response body and chunk framing"
severity: "low"
cvss: 2.0
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["http-clients", "python", "runtime"]
not_affected_if: []
published_at: "2026-10-27T20:17:11+00:00"
first_seen_at: "2026-10-27T20:33:27+00:00"
updated_at: "2026-10-27T20:35:36+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-103995", "first_seen_at": "2026-10-27T20:33:27+00:00"}]
---

# Python: lenient integer parsing misreads HTTP response body and chunk framing

Python's HTTP response body and chunked-transfer parsing accepts non-hex or negative integers where it should reject them. An attacker controlling a response could make the parser misinterpret where a body or chunk ends, which can desync the response contents.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-27T20:33:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-103995

## Documents

- [advisory] Python security-announce: [Security-announce][CVE-2026-103995] Lenient parsing of integers for response body and chunk framing https://mail.python.org/archives/list/security-announce@python.org/message/6TLH7YBU4HJIFBTBCEPAAK2I2F4KQBRB/

## From the sources

Response body and chunk parsing would handle non-hex or negative integers incorrectly which could result in misinterpreting HTTP response contents.

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