---
id: CVE-2023-27371
title: >-
  GNU libmicrohttpd before 0.9.76 allows remote DoS (Denial of Service) due to
  improper parsing of a multipart/form-data boundary in the postprocessor.c
  MHD_create_post_processor() method
summary: >-
  GNU libmicrohttpd before 0.9.76 allows remote DoS (Denial of Service) due to
  improper parsing of a multipart/form-data boundary in the postprocessor.c
  MHD_create_post_processor() method. This allows an attacker to remotely send a
  malicio…
severity: medium
cvss: 5.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-125
vendor: gnu
product: libmicrohttpd
affected:
  - libmicrohttpd < 0.9.76
patched:
  - libmicrohttpd 0.9.76
published: '2023-02-28'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T23:17:15.870'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-27371'
references:
  - url: >-
      https://git.gnunet.org/libmicrohttpd.git/commit/?id=6d6846e20bfdf4b3eb1b592c97520a532f724238
    label: cve@mitre.org
  - url: 'https://github.com/0xhebi/CVEs/tree/main/GNU%20Libmicrohttpd'
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2023/03/msg00029.html'
    label: cve@mitre.org
  - url: 'https://lists.gnu.org/archive/html/libmicrohttpd/2023-02/msg00000.html'
    label: cve@mitre.org
  - url: >-
      https://git.gnunet.org/libmicrohttpd.git/commit/?id=6d6846e20bfdf4b3eb1b592c97520a532f724238
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/0xhebi/CVEs/tree/main/GNU%20Libmicrohttpd'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2023/03/msg00029.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.gnu.org/archive/html/libmicrohttpd/2023-02/msg00000.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.01253
epssPercentile: 0.68871
ingestedAt: '2026-10-15T00:02:07.128Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2025-03-11T15:18:56.784683Z'
---

## Overview

GNU libmicrohttpd before 0.9.76 allows remote DoS (Denial of Service) due to improper parsing of a multipart/form-data boundary in the postprocessor.c MHD_create_post_processor() method. This allows an attacker to remotely send a malicious HTTP POST packet that includes one or more '\0' bytes in a multipart/form-data boundary field, which - assuming a specific heap layout - will result in an out-of-bounds read and a crash in the find_boundary() function.

## Affected

- `libmicrohttpd < 0.9.76`

## Remediation

Upgrade past the affected range:

- `libmicrohttpd 0.9.76`