Description
In PuTTY versions before 0.71 on Unix, a remotely triggerable buffer overflow exists in any kind of server-to-client forwarding.
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 | putty | 0.70-6 | — |
| Debian 13 | putty | 0.70-6 | — |
| Debian 12 | putty | 0.70-6 | — |
| Debian 9 | putty | 0.67-3+deb9u1 | DSA-4423-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | putty | No fix yet | — |
| Ubuntu 16.04 LTS | putty | 0.67-3+deb9u1build0.16.04.1 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 | putty | 0.71-bp150.4.3.1 | openSUSE-SU-2019:1123-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.0 | putty | 0.71-lp150.9.1 | openSUSE-SU-2019:1113-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | putty | 0.71-r0 | — |
| Alpine v3.23 | putty | 0.71-r0 | — |
| Alpine v3.22 | putty | 0.71-r0 | — |
| Alpine v3.21 | putty | 0.71-r0 | — |
| Alpine v3.20 | putty | 0.71-r0 | — |
Show 14 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | putty | 0.71-r0 | — |
| Alpine v3.18 | putty | 0.71-r0 | — |
| Alpine v3.17 | putty | 0.71-r0 | — |
| Alpine v3.16 | putty | 0.71-r0 | — |
| Alpine v3.15 | putty | 0.71-r0 | — |
| Alpine v3.14 | putty | 0.71-r0 | — |
| Alpine v3.13 | putty | 0.71-r0 | — |
| Alpine v3.12 | putty | 0.71-r0 | — |
| Alpine v3.11 | putty | 0.71-r0 | — |
| Alpine v3.10 | putty | 0.71-r0 | — |
| Alpine v3.9 | putty | 0.71-r0 | — |
| Alpine v3.8 | putty | 0.71-r0 | — |
| Alpine v3.7 | putty | 0.71-r0 | — |
| Alpine v3.6 | putty | 0.71-r0 | — |
Advisories 3
- DSA-4423-1 putty - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2019:1113-1 Security update for putty SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1123-1 Security update for putty SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
- FEDORA-2019-5776dfe300 vendor-advisory
- FEDORA-2019-9e1a1cd634 vendor-advisory
- openSUSE-SU-2019:1113 vendor-advisory
- openSUSE-SU-2019:1123 vendor-advisory
- 20190403 [SECURITY] [DSA 4423-1] putty security update mailing-list
- https://security.netapp.com/advisory/ntap-20190404-0001/
- DSA-4423 vendor-advisory