CVE-2026-6276Patch(haxx / curl)

LOWCVSS 7.5 · HIGH

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch haxx curl systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

0.5/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-346CWE-319

Priority

LOW

Exploitation

NONE

PoC

YES

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • curl

Threat summary

  • Patch or workaround signal is available
  • 7 mentions across 5 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 3 signals
  • Technical details provided in 3 signals
  • General: 2 classified signals
  • Disclosure: 2 classified signals
  • Peaked 3d ago at 2 mentions (2026-04-30); latest day: 1
  • 7 total mentions across 5 days

Affected systems

Vendors
Products
curl

Deep dive

Activity timeline7 mentions / 5d
01122Mentions · 2026-04-29: 1Mentions · 2026-04-30: 2Mentions · 2026-05-02: 1Mentions · 2026-05-11: 2Mentions · 2026-07-13: 1Patch / Workaround · 2026-05-11: 2Patch / Workaround · 2026-07-13: 1Technical Details · 2026-04-30: 1Technical Details · 2026-05-02: 1Technical Details · 2026-07-13: 104-2904-3005-0205-1107-13
Signal classification3 categories
Patch
342.9%
General
228.6%
Disclosure
228.6%
Referenced assets6 URLs
Classification over time
DateTotalLabels
2026-04-291
General1
2026-04-302
Disclosure1General1
2026-05-021
Disclosure1
2026-05-112
Patch2
2026-07-131
Patch1
Full discourse7 posts
  • 草薙 沙耶(KUSANAGI)@kusanagi_saya
    Patch

    kusanagi-curl モジュール更新情報 8.20.0-1 https://kusanagi.tokyo/releases/24476/ KUSANAGI 9 を構成している各モジュールのアップデートを行いました。 アップデートにより適用される各モジュールのバージョンは、以下のとおりとなります。 curl 8.20.0-1 この更新には脆弱性(CVE-2026-7168, CVE-2026-7009, CVE-2026-6429, CVE-2026-6276, CVE-2026-6253, CVE-2026-5773, CVE-2026-5545, CVE-2...

    Post summary

    The kusanagi‑curl module update addresses multiple CVEs, but contains no exploit, PoC, or active exploitation detail.

    0101085
    200 followersView on X
  • Open Source Security mailing list@oss_security
    Disclosure

    curl CVE-2026-6253: proxy credentials leak over redirect-to proxy CVE-2026-7009: OCSP stapling bypass with Apple SecTrust CVE-2026-6276: stale custom cookie host causes cookie leak CVE-2026-7168: cross-proxy Digest auth state leak 2/2

    Post summary

    The post enumerates several CVE identifiers with concise descriptions of leaked information, presenting an initial disclosure of new vulnerabilities without any PoC, exploit, or patch details.

    00010211
    4.5K followersView on X
  • TECHEPAGES@techepages
    Patch

    9 curl CVEs patched in Debian 13.6 🚨 🔵 CVE-2026-3783/6253 – token & credential leaks on redirects 🔵 CVE-2026-3805/5773 – SMB UAF & wrong reuse 🔵 CVE-2026-1965/5545 – Negotiate auth bypass 🔵 CVE-2026-3784 – proxy auth bypass (CVSS 6.5) 🔵 CVE-2026-6276 – cookie leak 🔵 CVE-2026-4873 – TLS bypass apt upgrade ⬆️

    Post summary

    Debian 13.6 has patched nine curl CVEs covering credential leaks, authentication bypasses, and other vulnerabilities; users are urged to run an apt upgrade.

    0000064
    19 followersView on X
  • 草薙 沙耶(KUSANAGI)@kusanagi_saya
    Patch

    kusanagi-curl Module Update 8.20.0-1 https://kusanagi.tokyo/en/releases/24477/ KUSANAGI 9 modules have been updated. The updated modules are as follows: curl 8.20.0-1 This update includes support for vulnerability(CVE-2026-7168, CVE-2026-7009, CVE-2026-6429, CVE-2026-6276, CVE-2026-6253,...

    Post summary

    The kusanagi-curl module 8.20.0-1 update patches several CVEs (CVE‑2026‑7168, CVE‑2026‑7009, CVE‑2026‑6429, CVE‑2026‑6276, CVE‑2026‑6253) without providing exploitation or PoC details.

    0000040
    200 followersView on X
  • H1 Disclosed - Public Disclosures@h1Disclosed
    Disclosure

    ⚡ CVE-2026-6276: stale custom cookie host causes cookie leak 👨🏻‍💻 arkss ➟ curl 🟨 Low 💰 None 🔗 https://hackerone.com/reports/3671818 #bugbounty #bugbountytips #cybersecurity #infosec https://t.co/bDioaYIIeH

    Post summary

    The tweet discloses CVE-2026-6276, a low‑severity cookie‑leak vulnerability caused by a stale custom cookie host, and links to a HackerOne report, but provides no PoC, exploit, or patch details.

    00000331
    10.2K followersView on X
  • Autumn Good@autumn_good_35
    General

    curlで8件の脆弱性 CVE-2026-7168 CVE-2026-7009 CVE-2026-6429 CVE-2026-6276 CVE-2026-6253 CVE-2026-5773 CVE-2026-5545 CVE-2026-4873 Published vulnerabilities for curl/libcurl https://curl.se/docs/security.html

    Post summary

    The snippet enumerates eight curl/libcurl CVE identifiers and provides a link to the curl security page, offering no further detail about exploits, patches, or technical specifics.

    00000396
    6.8K followersView on X
  • Vulmon Vulnerability Feed@VulmonFeeds
    General

    CVE-2026-6276 [ADVISORY] curl https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-6276 Customizable Vulnerability Alerts: https://alerts.vulmon.com/?utm_source=twitter&utm_medium=social&utm_campaign=2102281&utm_content=4

    Post summary

    The tweet mentions CVE‑2026‑6276 related to curl and provides a link to an advisory and alert service, but offers no further vulnerability details or actionable information.

    0000043
    4.0K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Apphaxxcurl---

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