Medium severity · published May 25, 2026
CVE-2026-48850
PuTTY 0.72 before 0.84 has a double free in RSA KEX
5.9
CVSS
0.3%
EPSS
No
On KEV
Description
PuTTY 0.72 before 0.84 has a double free in RSA KEX.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 25% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PU
PuTTY · PuTTY
0.72 before 0.84 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48850
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-48850
Release Notes
https://lists.tartarus.org/pipermail/putty-announce/2026/000042.html
Patch
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/rsakex-double-free.html
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