---
schema_version: '1.0'
id: security-20260708-8cf62f
url: https://osv.dev/vulnerability/CVE-2026-6253
url_hash: 8cf62f43e52c318a0f413aa27ec9402508318a342ddc3d69632c6ecd266e8d4f
canonical_url: https://osv.dev/vulnerability/CVE-2026-6253
source: osv:nvd
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-6253
- severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- https://github.com/curl/curl
- GIT
lang: en
published_at: '2026-05-13T08:28:03Z'
fetched_at: '2026-07-08T15:37:25Z'
updated_at: '2026-07-08T15:38:04Z'
status: published
content_hash: d9ae39f0d3d8908db8e64bc0ad3ed88a5e6550eab759b32d2d7d3fc5b0d03f98
license_note: full
summary: proxy credentials leak over redirect-to proxy
summary_source: rss
summary_en: proxy credentials leak over redirect-to proxy
entities:
- name: CVE-2013-0074
  type: naturalobject
- name: GitHub
  type: organization
- name: earlyappleleaks
  type: person
- name: Overcrowded Bus
  type: artifact
key_facts: []
related: []
related_auto:
- name: agent_openclaw
  type: person
  weight: 1.0
- name: CVSS score
  type: concept
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- name: AI Agent
  type: artifact
  weight: 1.0
- name: Hy3
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- name: OpenClaw
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title: 'CVE-2026-6253: proxy credentials leak over redirect-to proxy'
---

# CVE-2026-6253: proxy credentials leak over redirect-to proxy

## TL;DR
proxy credentials leak over redirect-to proxy

## Key Points
- cve / CVE-2026-6253 / severity:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H / https://github.com/curl/curl / GIT

## Details
**Severity:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
**Advisory:** CVE-2026-6253

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

**Details:**
curl might erroneously pass on credentials for a first proxy to a second
proxy.

This can happen when the following conditions are true:

1. curl is setup to use specific different proxies for different URL schemes
2. the first proxy needs credentials
3. the second proxy uses no credentials
4. while using the first proxy (using say `http://`), curl is asked to follow
   a redirect to a URL using another scheme (say `https://`), accessed using a
   second, different, proxy

**References:**
- http://www.openwall.com/lists/oss-security/2026/04/29/11
- https://curl.se/docs/CVE-2026-6253.html
- https://curl.se/docs/CVE-2026-6253.json
- https://hackerone.com/reports/3669637
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6253.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-6253

_Data: OSV.dev (upstream: nvd) — https://osv.dev/vulnerability/CVE-2026-6253_

## Source
元記事: [CVE-2026-6253: proxy credentials leak over redirect-to proxy](https://osv.dev/vulnerability/CVE-2026-6253) — published 2026-05-13T08:28:03Z