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TI-2020-15960 Aliases CVE-2020-26117GHSA-cx25-8g49-fx7q

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers…

Priority MEDIUM 41CWE-295Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · High · None
Fix status
Partial Red Hat: 1 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-295.

Summary

In rfb/CSecurityTLS.cxx and rfb/CSecurityTLS.java in TigerVNC before 1.11.0, viewers mishandle TLS certificate exceptions. They store the certificates as authorities, meaning that the owner of a certificate could impersonate any server after a client had added an exception.

Why it matters now

EPSS 0.0306 87th percentileScored 2026-11-07
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:tigervnc:tigervnc:*:*:*:*:*:*:*:*before 1.11.0VulnerableTigerVNC
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*15.2VulnerableopenSUSE
  • cpe:2.3:a:tigervnc:tigervnc:*:*:*:*:*:*:*:* Versions before 1.11.0 Vulnerable ·TigerVNC
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
  • cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:* Versions 15.2 Vulnerable ·openSUSE

Remediation

Red Hat 1 advisory

  • RHSA-2021:1783 Released 2021-05-18 · Red Hat rating Moderate
    tigervnc security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 8) tigervnc-1.11.0-6.el8, tigervnc-icons-1.11.0-6.el8, tigervnc-license-1.11.0-6.el8 +4

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2021:1783

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-26117
  2. 2026-10-03 Alias added: GHSA-cx25-8g49-fx7q

References

Patch 4

Advisory 5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences