---
schema_version: '1.0'
id: security-20260708-8a5880
url: https://osv.dev/vulnerability/CVE-2026-5545
url_hash: 8a58809b4cf19a237c89c817a6262a61f607431401653fde54f84cf2d7691f77
canonical_url: https://osv.dev/vulnerability/CVE-2026-5545
source: osv:nvd
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-5545
- severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
- https://github.com/curl/curl
- GIT
lang: en
published_at: '2026-05-13T08:27:26Z'
fetched_at: '2026-07-08T15:37:25Z'
updated_at: '2026-07-08T15:37:33Z'
status: published
content_hash: 156c1dd433b35e481b9dbf416c6f9098297bb98f2ed96e0dd3ef5d9319bd337d
license_note: full
summary: wrong reuse of HTTP Negotiate connection
summary_source: rss
summary_en: wrong reuse of HTTP Negotiate connection
entities:
- name: CVE-2013-0074
  type: naturalobject
- name: GitHub
  type: organization
- name: HTTPクライアント型エージェント
  type: UNKNOWN
- name: ConnectionPooler
  type: concept
key_facts: []
related: []
related_auto:
- name: agent_openclaw
  type: person
  weight: 1.0
- name: CVSS score
  type: concept
  weight: 1.0
- name: AI Agent
  type: artifact
  weight: 1.0
- name: Hy3
  type: artifact
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- name: OpenClaw
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title: 'CVE-2026-5545: wrong reuse of HTTP Negotiate connection'
---

# CVE-2026-5545: wrong reuse of HTTP Negotiate connection

## TL;DR
wrong reuse of HTTP Negotiate connection

## Key Points
- cve / CVE-2026-5545 / severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N / https://github.com/curl/curl / GIT

## Details
**Severity:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N
**Advisory:** CVE-2026-5545

**Affected (your watchlist):**
- `GIT:https://github.com/curl/curl` curl-8_9_1 → no fixed version listed [mac]

**Details:**
libcurl might in some circumstances reuse the wrong connection when asked to
do an authenticated HTTP(S) request after a Negotiate-authenticated one, when
both use the same host.

libcurl features a pool of recent connections so that subsequent requests can
reuse an existing connection to avoid overhead.

When reusing a connection a range of criteria must be met. Due to a logical
error in the code, a request that was issued by an application could
wrongfully reuse an existing connection to the same server that was
authenticated using different credentials.

An application that first uses Negotiate authentication to a server with
`user1:password1` and then does another operation to the same server asking
for any authentication method but for `user2:password2` (while the previous
connection is still alive) - the second request gets confused and wrongly
reuses the same connection and sends the new request over that connection
thinking it uses a mix of user1's and user2's credentials when it is in fact
still using the connection authenticated for user1...

**References:**
- https://curl.se/docs/CVE-2026-5545.html
- https://curl.se/docs/CVE-2026-5545.json
- https://hackerone.com/reports/3642555
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5545.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-5545

_Data: OSV.dev (upstream: nvd) — https://osv.dev/vulnerability/CVE-2026-5545_

## Source
元記事: [CVE-2026-5545: wrong reuse of HTTP Negotiate connection](https://osv.dev/vulnerability/CVE-2026-5545) — published 2026-05-13T08:27:26Z