| Name | CVE-2026-48850 |
| Description | PuTTY 0.72 before 0.84 has a double free in RSA KEX. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| putty (PTS) | bullseye | 0.74-1+deb11u2 | vulnerable |
| bullseye (security) | 0.74-1+deb11u1 | vulnerable |
| bookworm | 0.78-2+deb12u2 | vulnerable |
| bookworm (security) | 0.78-2+deb12u1 | vulnerable |
| forky, trixie | 0.83-3 | vulnerable |
| sid | 0.84-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| putty | source | (unstable) | 0.84-1 | | | |
Notes
[trixie] - putty <no-dsa> (Minor issue)
[bookworm] - putty <no-dsa> (Minor issue)
https://lists.tartarus.org/pipermail/putty-announce/2026/000042.html
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/rsakex-double-free.html
Fixed by: https://git.tartarus.org/?p=simon/putty.git;a=commitdiff;h=ba3ed53e0bf6682f89940bc2c3e83da6b1524024 (0.84)