PuTTY 0.77 before 0.84 uses a copy of the PuTTY icon as a trust indication for TELNET data but...

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.

Basic information

Type
unreviewed
Severity
low
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-05-26 13:30:51 UTC
Updated
2026-05-26 13:30:56 UTC
NVD published
2026-05-25

EPSS Score

Score Percentile
0.03% 9.76%

CVSS Scores

Base score Version Severity Vector
3.1 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-451 User Interface (UI) Misrepresentation of Critical Information

References

cvelogic Threat Intelligence