CVE-2026-48851

Severity: low (CVSS 3.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-25 · updated 2026-07-24
Weakness: CWE-451

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 products

PuTTY: from 0.77 before 0.84 — fixed in 0.84

How to fix

Upgrade to a fixed version: PuTTY 0.84. Check the vendor advisory for mitigations.

References

https://lists.tartarus.org/pipermail/putty-announce/2026/000042.html
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/telnet-trust-sigil.html

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