CVE-2026-66032
Fixed in a distro release EPSS <1%CVSS 8.8
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.
Products: libssh2
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.21 | libssh2 | 1.11.1-r3 |
| Alpine 3.22 | libssh2 | 1.11.1-r3 |
| Alpine 3.23 | libssh2 | 1.11.1-r4 |
| Alpine 3.24 | libssh2 | 1.11.1-r4 |
| Amazon Linux 2 | libssh2 | 1.4.3-12.amzn2.2.9 |
| Amazon Linux 2 | libssh2-devel | 1.4.3-12.amzn2.2.9 |
| Amazon Linux 2 | libssh2-docs | 1.4.3-12.amzn2.2.9 |
| Amazon Linux 2023 | cargo-c | 0.10.21-1.amzn2023.0.1 |
| Amazon Linux 2023 | libssh2 | 1.10.0-1.amzn2023.0.6 |
| Amazon Linux 2023 | libssh2-devel | 1.10.0-1.amzn2023.0.6 |
| Amazon Linux 2023 | libssh2-docs | 1.10.0-1.amzn2023.0.6 |
| Chainguard | libssh2 | no fix |
| Chainguard | libssh2-dev | no fix |
| Chainguard | libssh2-doc | no fix |
| Debian 12 | libssh2 | 1.10.0-3+deb12u1 |
| Debian 13 | libssh2 | 1.11.1-1+deb13u2 |
| Debian 14 | libssh2 | 1.11.1-5 |
| Red Hat hummingbird 1 | libssh2 | 0:1.11.1-10.2.hum1 |
| Red Hat hummingbird 1 | libssh2-devel | 0:1.11.1-10.2.hum1 |
| Red Hat hummingbird 1 | libssh2-docs | 0:1.11.1-10.2.hum1 |
| Red Hat rhel els 7 | libssh2 | 0:1.8.0-4.el7_9.2 |
| Red Hat rhel els 7 | libssh2-devel | 0:1.8.0-4.el7_9.2 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | libssh2_org | 1.11.0-150000.4.35.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | libssh2_org | 1.11.0-150000.4.35.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Micro 5.3 | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Micro 5.4 | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Micro 5.5 | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | libssh2_org | 1.11.0-150600.20.6.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | libssh2_org | 1.11.0-29.18.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | libssh2_org | 1.11.0-150000.4.35.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | libssh2_org | 1.11.0-150600.20.6.1 |
| SUSE Linux Enterprise Server 16.0 | libssh2_org | 1.11.1-160000.5.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | libssh2_org | 1.11.0-29.18.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | libssh2_org | 1.11.0-150200.9.8.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | libssh2_org | 1.11.0-150600.20.6.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | libssh2_org | 1.11.1-160000.5.1 |
| SUSE Linux Micro 6.0 | libssh2_org | 1.11.0-4.1 |
| SUSE Linux Micro 6.1 | libssh2_org | 1.11.0-slfo.1.1_2.1 |
| SUSE Linux Micro 6.2 | libssh2_org | 1.11.1-160000.5.1 |
| Ubuntu 22.04 LTS | libssh2 | 1.10.0-3ubuntu0.1 |
| Ubuntu 24.04 LTS | libssh2 | 1.11.0-4.1ubuntu0.24.04.4 |
| Ubuntu 26.04 LTS | libssh2 | 1.11.1-1ubuntu0.26.04.4 |
| Ubuntu Pro 14.04 LTS | libssh2 | 1.4.3-2ubuntu0.2+esm4 |
| Ubuntu Pro 16.04 LTS | libssh2 | 1.5.0-2ubuntu0.1+esm3 |
| Ubuntu Pro 18.04 LTS | libssh2 | 1.8.0-1ubuntu0.1+esm1 |
| Ubuntu Pro 20.04 LTS | libssh2 | 1.8.0-2.1ubuntu0.1+esm1 |
| Wolfi | libssh2 | no fix |
| Wolfi | libssh2-dev | no fix |
| Wolfi | libssh2-doc | no fix |
| openSUSE Leap 16.0 | libssh2_org | 1.11.1-160000.5.1 |
| openSUSE Tumbleweed | libssh2_org | 1.11.1-4.1 |