CURL-CVE-2026-5545 wrong reuse of HTTP Negotiate connection

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTPS 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...

Authentication Bypass by Primary Weakness

Overview Affected versions of this package are vulnerable to Authentication Bypass by Primary Weakness via the reuse of HTTP Negotiate authenticated connections. An attacker can gain unauthorized access or perform actions with unintended credentials by making an authenticated HTTPS request after ...

PT-2026-35892

Name of the Vulnerable Software and Affected Versions libcurl affected versions not specified Description A logical error in the connection pooling mechanism allows libcurl to reuse an incorrect connection during authenticated HTTPS requests to the same host. If an application first performs a...

Fedora 44 : curl (2026-f13d888b0f)

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-f13d888b0f advisory. - Fix bad reuse of HTTP Negotiate connection CVE-2026-1965 - Fix token leak with redirect and netrc CVE-2026-3783 - Fix wrong proxy connection reuse...

CVE-2026-32952

go-ntlmssp is a Go package that provides NTLM/Negotiate authentication over HTTP. Prior to version 0.1.1, a malicious NTLM challenge message can causes an slice out of bounds panic, which can crash any Go process using ntlmssp.Negotiator as an HTTP transport. Version 0.1.1 patches the issue...

DEBIAN-CVE-2026-32952

go-ntlmssp is a Go package that provides NTLM/Negotiate authentication over HTTP. Prior to version 0.1.1, a malicious NTLM challenge message can causes an slice out of bounds panic, which can crash any Go process using ntlmssp.Negotiator as an HTTP transport. Version 0.1.1 patches the issue...

EUVD-2026-25374

go-ntlmssp is a Go package that provides NTLM/Negotiate authentication over HTTP. Prior to version 0.1.1, a malicious NTLM challenge message can causes an slice out of bounds panic, which can crash any Go process using ntlmssp.Negotiator as an HTTP transport. Version 0.1.1 patches the issue...

CVE-2026-32952

go-ntlmssp is a Go package that provides NTLM/Negotiate authentication over HTTP. Prior to version 0.1.1, a malicious NTLM challenge message can causes an slice out of bounds panic, which can crash any Go process using ntlmssp.Negotiator as an HTTP transport. Version 0.1.1 patches the issue...

Unity Linux 20.1060a / 20.1070a Security Update: kernel (UTSA-2026-013573)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-013573 advisory. In the Linux kernel, the following vulnerability has been resolved: cifs: Fix the error length of VALIDATENEGOTIATEINFO message Commit d5c7076b772a smb3: add smb3.1....

Unity Linux 20.1070e Security Update: kernel (UTSA-2026-010754)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-010754 advisory. An issue was discovered in ksmbd in the Linux kernel 5.15 through 5.19 before 5.19.2. fs/ksmbd/smb2pdu.c omits a kfree call in certain smb2handlenegotiate error...

Fedora 43 : curl (2026-66db242036)

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-66db242036 advisory. - Fix bad reuse of HTTP Negotiate connection CVE-2026-1965 - Fix token leak with redirect and netrc CVE-2026-3783 - Fix wrong proxy connection reuse...

Fedora 42 : curl (2026-907bbf2a13)

The remote Fedora 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-907bbf2a13 advisory. - fix bad reuse of HTTP Negotiate connection CVE-2026-1965 - fix token leak with redirect and netrc CVE-2026-3783 - fix wrong proxy connection reuse...

curl: Negotiate Authentication Premature on Connection Reuse

Summary: Curl 8.19.0+ inappropriately sends Negotiate authentication headers on reused keep-alive connections where authentication was already completed. Commit ab650379a8 June 2025 moved negotiate auth context to on-demand metadata storage, but during connection reuse the metadata gets cleared...

curl: curl: Authentication bypass due to incorrect connection reuse with Negotiate authentication

A flaw was found in curl. When an application uses libcurl to make multiple Negotiate-authenticated HTTP or HTTPS requests to the same server with different credentials, libcurl may incorrectly reuse an existing connection. This logical error can cause a subsequent request to be sent using the...

curl: Negotiate connection reuse with wrong credentials when using CURLAUTH_ANY

Summary: CVE-2026-1965 fixed connection reuse for Negotiate authentication by adding urlmatchauthnego in urlmatchconn at line 1244 of lib/url.c. When a first handle authenticates via Negotiate Kerberos on a connection and that connection returns to the pool, a second handle with different...

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

Summary: An attacker sharing a libcurl multi-handle connection pool can hijack another user's Negotiate/Kerberos-authenticated connection. When User A authenticates via Negotiate SPNEGO and the connection returns to the pool, User B using CURLAUTHANY with different credentials gets that connectio...

CLSA-2026-1774260216 Fix CVE(s): CVE-2026-1965, CVE-2026-3783, CVE-2026-3784

SECURITY UPDATE: reuse of connections using HTTP Negotiate - debian/patches/CVE-2026-1965.patch: fix reuse of connections using HTTP Negotiate and fix copy and paste urlmatchauthnego mistake. - CVE-2026-1965 Bearer token sent without checking auth is allowed - debian/patches/CVE-2026-3783.patch:...

CLSA-2026-1774259220 curl: Fix of 3 CVEs

CVE-2026-1965: fix incorrect connection reuse; prevent reuse of Negotiate- authenticated connections with different credentials and require authentication identity match - CVE-2026-3784: fix wrong proxy connection reuse with different credentials; check proxy user/password in proxyinfomatches to...

OESA-2026-1704 curl security update

cURL is a computer software project providing a library libcurl and command-line tool curl for transferring data using various protocols. Security Fixes: libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl feature...

SUSE-SU-2026:20760-1 Security update for curl

This update for curl fixes the following issues: - CVE-2026-1965: bad reuse of HTTP Negotiate connection bsc1259362. - CVE-2026-3783: token leak with redirect and netrc bsc1259363. - CVE-2026-3784: wrong proxy connection reuse with credentials bsc1259364. - CVE-2026-3805: use after free in SMB...