Description
Server-side memory exhaustion in Apache MINA SSHD 1.0.0 to 2.19.0 and 3.0.0-M1 to 3.0.0-M5, component sshd-sftp, in the SFTP v6 check-file-name/check-file-handle extension. Apache MINA SSHD is a Java library for client-side and server-side SSH.
Using a very small "block size" (for instance 256, which is the minimum) on a huge file generates many (file size / block size) hashes. The resulting SFTP reply message was accumulated fully in memory server-side, which could, with a suitably large (possibly sparse) file exhaust the server-side memory, taking down the server.
Users are recommended to upgrade to version 2.20.0 or 3.0.0-M6, which fix this issue by imposing a maximum limit on the size of the reply. Many SFTP implementations have a general limit on the size of SFTP messages anyway; typically 256kB as in OpenSSH or also in Apache MINA SSHD.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache MINA SSHD | 1.0.0 – < 2.20.0, 3.0.0-M1 – < 3.0.0-M6 | 2.20.0 |
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 | libmina-sshd-java | 2.20.1-1 | — |
| Debian 13 | libmina-sshd-java | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | mina2 | No fix yet | — |
| Ubuntu 24.04 LTS | mina | No fix yet | — |
| Ubuntu 22.04 LTS | mina | No fix yet | — |
| Ubuntu 20.04 LTS | mina +1 | No fix yet | — |
| Ubuntu 18.04 LTS | mina +1 | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | mina +1 | No fix yet | — |
| Ubuntu Pro 26.04 LTS | mina2 | No fix yet | — |
| Ubuntu Pro 24.04 LTS | mina2 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | mina2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLES 15 SP6 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLES 15 SP5 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLES 15 SP4 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLES for SAP 15 SP5 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLES for SAP 15 SP4 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLE HPC 15 SP5 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
| SLE HPC 15 SP4 | apache-sshd | 2.20.0-150200.5.19.1 | SUSE-SU-2026:4622-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache-sshd | 2.20.0-1.1 | openSUSE-SU-2026:11940-1 |
Advisories 2
- SUSE-SU-2026:4622-1 Security update for apache-sshd SUSE / openSUSE Security Updates · Oct 13, 2026
- openSUSE-SU-2026:11940-1 apache-sshd-2.20.0-1.1 on GA media SUSE / openSUSE Security Updates · Oct 2, 2026