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… (CVE-2026-48851)
Description
PuTTY versions from 0.65-2 through 0.84-1 use a copy of the PuTTY icon as a trust indicator for TELNET data, but the trust status is not cleared between proxy authentication and the main session. This could lead to misleading trust indications in the user interface. The vulnerability has a medium severity with a CVSS score of 3.1.
CVSS v3.1
Score 3.1low
Affected software
pkg:deb/ubuntu/putty?arch=source&distro=xenialpkg:deb/ubuntu/putty?arch=source&distro=bionicpkg:deb/ubuntu/putty?arch=source&distro=focalpkg:deb/ubuntu/putty?arch=source&distro=jammypkg:deb/ubuntu/putty?arch=source&distro=noblepkg:deb/ubuntu/putty?arch=source&distro=questingpkg:deb/ubuntu/putty?arch=source&distro=stonkingpkg:deb/ubuntu/putty?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
PuTTY versions 0.65-2 through 0.84-1 have a vulnerability where the trust status indicated by the PuTTY icon for TELNET data is not reset between proxy authentication and the main session. This means the icon may incorrectly show a trusted status when it should not, potentially misleading users about the security state of the connection. The issue affects multiple versions prior to 0.84-1 and has a CVSS 3.1 base score of 3.1, indicating low impact on confidentiality and availability but some integrity impact. No known exploits in the wild have been reported.
Potential Impact
The vulnerability may cause users to be misled about the trust status of TELNET connections due to the icon not being cleared properly. This could reduce the effectiveness of the trust indication mechanism but does not directly compromise confidentiality or availability. The integrity impact is low, and no active exploitation is known.
Mitigation Recommendations
No vendor advisory or patch information is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should consider upgrading to versions later than 0.84-1 if available, as the issue is fixed starting from that version.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-48851
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:16.04:LTS","Ubuntu:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.10","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
Threat ID: 6ad3f61d2cdf04f65666419f
Added to database: 10/17/2026, 22:26:37 UTC
Last enriched: 10/18/2026, 01:05:11 UTC
Last updated: 10/18/2026, 01:05:11 UTC
Views: 2
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