Vulnerability · Published May 25, 2026 · Assigned by mitre
CVE-2026-48851
Low 3.1
In plain English
A low-severity security flaw in PuTTY from PuTTY. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)3.1Low
Exploit odds (30 days)0.2%top 86.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
PuTTY 0.77 before 0.84 uses a copy of the PuTTY icon as a trust indication for TELNET data but the trust status is not cleared between proxy authentication and the main session.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | putty | no fix listed | DEBIAN-CVE-2026-48851 |
| Debian:13 | putty | no fix listed | DEBIAN-CVE-2026-48851 |
| Debian:14 | putty | 0.84-1 | DEBIAN-CVE-2026-48851 |
| Ubuntu:22.04:LTS | putty | no fix listed | UBUNTU-CVE-2026-48851 |
| Ubuntu:24.04:LTS | putty | no fix listed | UBUNTU-CVE-2026-48851 |
| Ubuntu:25.10 | putty | no fix listed | UBUNTU-CVE-2026-48851 |
| Ubuntu:26.04:LTS | putty | no fix listed | UBUNTU-CVE-2026-48851 |
| Ubuntu:26.10 | putty | no fix listed | UBUNTU-CVE-2026-48851 |
Affected products (as reported)
Weakness: CWE-451 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N