Description
libssh2 through 1.11.1, fixed in commit 2dae302, contains an out-of-bounds heap read vulnerability in the sftp_symlink() function in src/sftp.c that allows a malicious SSH server or man-in-the-middle attacker to disclose heap memory contents or cause a crash by sending a crafted SSH_FXP_NAME response. Attackers can supply a link_len value larger than the actual packet data in SSH_FXP_NAME responses for SFTP READLINK and REALPATH operations, triggering a heap buffer over-read of up to target_len minus one bytes due to the missing validation of available packet buffer size before the memcpy operation.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| libssh2 | libssh2 | ≤ 1.11.1 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libssh2 | 1.11.1-4 | — |
| Debian 13 | libssh2 | 1.11.1-1+deb13u1 | — |
| Debian 12 | libssh2 | 1.10.0-3+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | libssh2 | 1.11.1-1ubuntu0.26.04.2 | — |
| Ubuntu 25.10 | libssh2 | 1.11.1-1ubuntu0.25.10.2 | — |
| Ubuntu 24.04 LTS | libssh2 | 1.11.0-4.1ubuntu0.24.04.2 | — |
| Ubuntu 22.04 LTS | libssh2 | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | libssh2 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | libssh2 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | libssh2 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | libssh2 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | libssh2 +2 | 1.11.1-9.hum1 | RHSA-2026:30132 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | libssh2_org | 1.11.0-150600.20.6.1 | SUSE-SU-2026:3541-1 |
| SLES 15 SP6 | libssh2_org | 1.11.0-150600.20.6.1 | SUSE-SU-2026:3541-1 |
| SLES 15 SP5 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLES 15 SP4 | libssh2_org | 1.11.0-150000.4.35.1 | SUSE-SU-2026:4095-1, SUSE-SU-2026:3526-1 |
| SLES 12 SP5 | libssh2_org | 1.11.0-29.18.1 | SUSE-SU-2026:3525-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | libssh2_org | 1.11.1-160000.5.1 | SUSE-SU-2026:23225-1, SUSE-SU-2026:23214-1 |
| SLES for SAP 15 SP6 | libssh2_org | 1.11.0-150600.20.6.1 | SUSE-SU-2026:3541-1 |
| SLES for SAP 15 SP5 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLES for SAP 15 SP4 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLES 16.0 | libssh2_org | 1.11.1-160000.5.1 | SUSE-SU-2026:23225-1, SUSE-SU-2026:23214-1 |
| SLE Micro 6.2 | libssh2_org | 1.11.1-160000.5.1 | SUSE-SU-2026:23049-1 |
| SLE Micro 6.1 | libssh2_org | 1.11.0-slfo.1.1_2.1 | SUSE-SU-2026:23187-1 |
| SLE Micro 6.0 | libssh2_org | 1.11.0-4.1 | SUSE-SU-2026:23245-1 |
| SLE Micro 5.5 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLE Micro 5.4 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLE Micro 5.3 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLE HPC 15 SP5 | libssh2_org | 1.11.0-150200.9.8.1 | SUSE-SU-2026:3526-1 |
| SLE HPC 15 SP4 | libssh2_org | 1.11.0-150000.4.35.1 | SUSE-SU-2026:4095-1, SUSE-SU-2026:3526-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | libssh2_org | 1.11.1-3.1 | openSUSE-SU-2026:11109-1 |
| openSUSE Leap 16.0 | libssh2_org | 1.11.1-160000.5.1 | openSUSE-SU-2026:21549-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libssh2 | 1.11.1-r4 | — |
| Alpine v3.24 | rust +1 | 1.96.1-r0 | — |
| Alpine v3.23 | libssh2 | 1.11.1-r4 | — |
| Alpine v3.22 | libssh2 | 1.11.1-r3 | — |
| Alpine v3.21 | libssh2 | 1.11.1-r3 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libssh2 | 1.11.1-4 | — |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | libssh2 +2 | 1.11.1-r7 | — |
Advisories 14
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- RHSA-2026:30132 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 6, 2026
- SUSE-SU-2026:4095-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Sep 14, 2026
- WID-SEC-2026-2007 libssh2: Schwachstelle ermöglicht Denial of Service und Offenlegung von Informationen BSI CERT-Bund (WID) · Sep 13, 2026
- SUSE-SU-2026:23245-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23225-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23214-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23187-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 26, 2026
- openSUSE-SU-2026:21549-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 12, 2026
- SUSE-SU-2026:23049-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 12, 2026
- SUSE-SU-2026:3541-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 11, 2026
- SUSE-SU-2026:3525-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 8, 2026
- SUSE-SU-2026:3526-1 Security update for libssh2_org SUSE / openSUSE Security Updates · Aug 8, 2026
- openSUSE-SU-2026:11109-1 libssh2-1-1.11.1-3.1 on GA media SUSE / openSUSE Security Updates · Jun 24, 2026
References
- Researcher Pull Request issue-tracking patch
- Maintainer Pull Request issue-tracking patch
- Patch Commit patch
- https://www.vulncheck.com/advisories/libssh2-heap-buffer-over-read-via-sftp-symlink-in-sftp-c third-party-advisory