CVE catalog
CVE-2026-66032
libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authentica
- Severity
- High · CVSS 8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.45% · Oct 25, 2026
libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | libssh2 | sid | 1.11.1-6 | fixed |
| Debian | libssh2 | forky | 1.11.1-6 | fixed |
| Debian | libssh2 | trixie | 1.11.1-1+deb13u2 | fixed |
| Debian | libssh2 | trixie-security | 1.11.1-1+deb13u1 | vulnerable |
| Debian | libssh2 | bookworm | 1.10.0-3 | vulnerable |
| Debian | libssh2 | bookworm-security | 1.10.0-3+deb12u1 | fixed |
| Ubuntu | libssh2 | noble | 1.11.0-4.1ubuntu0.24.04.4 | fixed |
| Ubuntu | libssh2-1-dev | noble | 1.11.0-4.1ubuntu0.24.04.4 | fixed |
| Ubuntu | libssh2-1t64 | noble | 1.11.0-4.1ubuntu0.24.04.4 | fixed |
| Ubuntu | libssh2 | pro | 1.8.0-2.1build1 | vulnerable |
| Ubuntu | libssh2 | pro | 1.8.0-2.1ubuntu0.1 | vulnerable |
| Ubuntu | libssh2 | pro | 1.8.0-2.1ubuntu0.1+esm1 | fixed |
| Ubuntu | libssh2 | 22.04 | 1.9.0-3 | vulnerable |
| Ubuntu | libssh2 | 22.04 | 1.10.0-2 | vulnerable |
| Ubuntu | libssh2 | 22.04 | 1.10.0-2build1 | vulnerable |
| Ubuntu | libssh2 | 22.04 | 1.10.0-3 | vulnerable |
| Ubuntu | libssh2 | 22.04 | 1.10.0-3ubuntu0.1 | fixed |
| Ubuntu | libssh2 | 24.04 | 1.11.0-2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-3 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1build1 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1build2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.1 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.3 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.4 | fixed |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1build1 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1build2 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.1 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.2 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.3 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.4 | fixed |
| Ubuntu | libssh2 | 24.04 | 1.11.0-2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-3 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1build1 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1build2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.1 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.2 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.3 | vulnerable |
| Ubuntu | libssh2 | 24.04 | 1.11.0-4.1ubuntu0.24.04.4 | fixed |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1build1 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1build2 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.1 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.2 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.3 | vulnerable |
| Ubuntu | libssh2 | 26.04 | 1.11.1-1ubuntu0.26.04.4 | fixed |
| Alpine | libssh2 | 3.21 | 1.11.1-r3 | fixed |
| Alpine | libssh2 | 3.22 | 1.11.1-r3 | fixed |
| Alpine | libssh2 | 3.23 | 1.11.1-r4 | fixed |
| Alpine | libssh2 | 3.24 | 1.11.1-r4 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | libssh2 | source | sid | 1.11.1-5 | not yet assigned | Not reported | [1142856] |
| Debian | libssh2 | source | forky | 1.11.1-5 | not yet assigned | Not reported | [1142856] |
| Debian | libssh2 | source | trixie | 1.11.1-1+deb13u2 | not yet assigned | Not reported | [1142856] |
| Debian | libssh2 | source | bookworm | 1.10.0-3+deb12u1 | not yet assigned | Not reported | [1142856] |
| Ubuntu | libssh2 | deb | noble | 1.11.0-4.1ubuntu0.24.04.4 | Not reported | Not reported | Not reported |
| Ubuntu | libssh2-1-dev | deb | noble | 1.11.0-4.1ubuntu0.24.04.4 | Not reported | Not reported | Not reported |
| Ubuntu | libssh2-1t64 | deb | noble | 1.11.0-4.1ubuntu0.24.04.4 | Not reported | Not reported | Not reported |
| Ubuntu | libssh2 | deb | pro | 1.8.0-2.1ubuntu0.1+esm1 | Not reported | UBUNTU-CVE-2026-66032 | Not reported |
| Ubuntu | libssh2 | deb | 22.04 | 1.10.0-3ubuntu0.1 | Not reported | UBUNTU-CVE-2026-66032 | Not reported |
| Ubuntu | libssh2 | deb | 24.04 | 1.11.0-4.1ubuntu0.24.04.4 | Not reported | UBUNTU-CVE-2026-66032 | Not reported |
| Ubuntu | libssh2 | deb | 26.04 | 1.11.1-1ubuntu0.26.04.4 | Not reported | UBUNTU-CVE-2026-66032 | Not reported |
| Ubuntu | libssh2 | deb | 24.04 | 1.11.0-4.1ubuntu0.24.04.4 | Not reported | USN-8722-1 | Not reported |
| Ubuntu | libssh2 | deb | 26.04 | 1.11.1-1ubuntu0.26.04.4 | Not reported | USN-8722-1 | Not reported |
| Alpine | libssh2 | apk | 3.21 | 1.11.1-r3 | Not reported | ALPINE-CVE-2026-66032 | Not reported |
| Alpine | libssh2 | apk | 3.22 | 1.11.1-r3 | Not reported | ALPINE-CVE-2026-66032 | Not reported |
| Alpine | libssh2 | apk | 3.23 | 1.11.1-r4 | Not reported | ALPINE-CVE-2026-66032 | Not reported |
| Alpine | libssh2 | apk | 3.24 | 1.11.1-r4 | Not reported | ALPINE-CVE-2026-66032 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [libssh2-1]Affected
Source package: [libssh2]
Details (2)
1.10.0-3+b1· amd64 · bookwormAffected · Fixed:
1.10.0-3+deb12u1nvd · libssh2 · debian · bookworm; nvd · libssh2 · debian · 12
1.10.0-3+b1· arm64 · bookwormAffected · Fixed:
1.10.0-3+deb12u1nvd · libssh2 · debian · bookworm; nvd · libssh2 · debian · 12
- [libssh2-1-dev]Affected
Source package: [libssh2]
Details (2)
1.10.0-3+b1· amd64 · bookwormAffected · Fixed:
1.10.0-3+deb12u1nvd · libssh2 · debian · bookworm; nvd · libssh2 · debian · 12
1.10.0-3+b1· arm64 · bookwormAffected · Fixed:
1.10.0-3+deb12u1nvd · libssh2 · debian · bookworm; nvd · libssh2 · debian · 12
[Debian 13 (Trixie)]
- [libssh2-1-dev]Affected
Source package: [libssh2]
Details (4)
1.11.1-1+deb13u1· amd64 · trixieAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· arm64 · trixieAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· amd64 · trixie-securityAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· arm64 · trixie-securityAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
- [libssh2-1t64]Affected
Source package: [libssh2]
Details (4)
1.11.1-1+deb13u1· amd64 · trixieAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· arm64 · trixieAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· amd64 · trixie-securityAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
1.11.1-1+deb13u1· arm64 · trixie-securityAffected · Fixed:
1.11.1-1+deb13u2nvd · libssh2 · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_11454-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-66032]
- [https://osv.dev/vulnerability/ALPINE-CVE-2026-66032]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-66032]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-66032]
- [https://osv.dev/vulnerability/USN-8722-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-66032]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66032.json]
- [https://ubuntu.com/security/notices/USN-8722-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-2516.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]