Use-after-free in cURL - CVE-2026-3805

Vulnerability identifier: #VU123887

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-3805

CWE-ID: CWE-416

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a use-after-free error when doing a second SMB request to the same host again. A remote attacker can gain access to sensitive information on the system.

cURL
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Real Time 15
SUSE Manager Server
SUSE Manager Retail Branch Server
SUSE Manager Proxy
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Basesystem Module
openSUSE Leap
Ubuntu
Fedora
LANTIME Operating System Firmware (LTOS)
curl (Ubuntu package)
curl
curl-debugsource
libcurl4
curl-debuginfo
libcurl4-debuginfo
libcurl-devel
libcurl4-32bit-debuginfo
libcurl4-32bit
libcurl-mini4
curl-mini-debugsource
libcurl-mini4-debuginfo
curl-zsh-completion
libcurl-devel-doc
curl-fish-completion
libcurl-devel-32bit
libcurl-devel-64bit
libcurl4-64bit
libcurl4-64bit-debuginfo

Install updates from vendor's website.

cURL - update to 8.19.0
LANTIME Operating System Firmware (LTOS) - update to 7.10.009
curl (Ubuntu package) - addressed in versions 7.81.0-1ubuntu1.23, 8.5.0-2ubuntu10.8, 8.14.1-2ubuntu1.2
curl - addressed in versions 8.11.1-8.fc42, 8.15.0-6.fc43, 8.18.0-6.fc44
curl-debugsource - addressed in versions 8.14.1-150200.4.103.1, 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl4 - addressed in versions 8.14.1-150200.4.103.1, 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
curl-debuginfo - addressed in versions 8.14.1-150200.4.103.1, 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl4-debuginfo - addressed in versions 8.14.1-150200.4.103.1, 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
curl - addressed in versions 8.14.1-150200.4.103.1, 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl-devel - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl4-32bit-debuginfo - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl4-32bit - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1, 8.14.1-150700.7.14.1
libcurl-mini4 - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
curl-mini-debugsource - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl-mini4-debuginfo - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
curl-zsh-completion - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl-devel-doc - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
curl-fish-completion - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl-devel-32bit - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl-devel-64bit - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl4-64bit - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1
libcurl4-64bit-debuginfo - addressed in versions 8.14.1-150400.5.80.1, 8.14.1-150600.4.40.1

• https://curl.se/docs/CVE-2026-3805.html

• Multiple vulnerabilities in curl
• Ubuntu update for curl
• SUSE update for curl
• SUSE update for curl
• SUSE update for curl
• SUSE update for curl
• Fedora 44 update for curl
• Fedora 43 update for curl
• Fedora 42 update for curl
• Meinberg LANTIME firmware update for third-party components