TightVNC before 1.2.6 generates the same challenge string for multiple connections, which…
Priority LOW 37Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- — Not recorded in CVSS 2.0
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Partial · Partial · Partial
- Fix status
- Fixed
Attack profile from CVSS 2.0 · NVD. Fix status from CNA and Red Hat.
Summary
TightVNC before 1.2.6 generates the same challenge string for multiple connections, which allows remote attackers to bypass VNC authentication by sniffing the challenge and response of other users.
Why it matters now
EPSS 0.02404 84th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:tightvnc:tightvnc:1.2.0:*:*:*:*:*:*:* | 1.2.0 | Vulnerable | Tightvnc |
| cpe:2.3:a:tightvnc:tightvnc:1.2.1:*:*:*:*:*:*:* | 1.2.1 | Vulnerable | Tightvnc |
| cpe:2.3:a:tightvnc:tightvnc:1.2.3:*:*:*:*:*:*:* | 1.2.3 | Vulnerable | Tightvnc |
| cpe:2.3:a:tightvnc:tightvnc:1.2.4:*:*:*:*:*:*:* | 1.2.4 | Vulnerable | Tightvnc |
| cpe:2.3:a:tightvnc:tightvnc:1.2.5:*:*:*:*:*:*:* | 1.2.5 | Vulnerable | Tightvnc |
- cpe:2.3:a:tightvnc:tightvnc:1.2.0:*:*:*:*:*:*:* Versions 1.2.0 Vulnerable ·Tightvnc
- cpe:2.3:a:tightvnc:tightvnc:1.2.1:*:*:*:*:*:*:* Versions 1.2.1 Vulnerable ·Tightvnc
- cpe:2.3:a:tightvnc:tightvnc:1.2.3:*:*:*:*:*:*:* Versions 1.2.3 Vulnerable ·Tightvnc
- cpe:2.3:a:tightvnc:tightvnc:1.2.4:*:*:*:*:*:*:* Versions 1.2.4 Vulnerable ·Tightvnc
- cpe:2.3:a:tightvnc:tightvnc:1.2.5:*:*:*:*:*:*:* Versions 1.2.5 Vulnerable ·Tightvnc
Remediation
Red Hat 2 advisories
- RHSA-2003:041 Released 2003-02-21 · Red Hat rating Moderate: : : Updated VNC packages fix replay and cookie vulnerabilities
- Red Hat Linux 7.0
- Red Hat Linux 7.1
- Red Hat Linux 7.2
- Red Hat Linux 7.3
- Red Hat Linux 8.0
- RHSA-2002:287 Released 2003-01-16 · Red Hat rating Moderatevnc security update
- Red Hat Enterprise Linux AS (Advanced Server) version 2.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AS (Advanced Server) version 2.1 | Fixed | RHSA-2002:287 |
| Red Hat Linux 7.0 | Fixed | RHSA-2003:041 |
| Red Hat Linux 7.1 | Fixed | RHSA-2003:041 |
| Red Hat Linux 7.2 | Fixed | RHSA-2003:041 |
| Red Hat Linux 7.3 | Fixed | RHSA-2003:041 |
| Red Hat Linux 8.0 | Fixed | RHSA-2003:041 |
Timeline
- 2026-10-02 Threatist record created from CVE-2002-1336
- 2026-10-03 Alias added: GHSA-fcjm-23wr-m9g6
References
More Tightvnc vulnerabilities
- TI-2019-05957 Buffer overflow in Kaspersky TightVNC CVSS 3.1CRITICAL 9.8
- TI-2009-00368 Multiple integer signedness errors in (1) UltraVNC 1.0.2 and 1.0.5 and (2) TightVnc 1.3.9… CVSS 2.0HIGH 10.0
- TI-2019-11763 Heap-based buffer overflow in Kaspersky TightVNC CVSS 3.1CRITICAL 9.8
- TI-2019-11762 Heap-based buffer overflow in Kaspersky TightVNC CVSS 3.1CRITICAL 9.8
- TI-2021-18987 Buffer Overflow in tvnviewer.exe via Crafted Packet in TightVNC Viewer 2.8.59 CVSS 3.1CRITICAL 9.8
- TI-2023-12438 TightVNC before v2.8.75 allows attackers to escalate privileges on the host operating… CVSS 3.1CRITICAL 9.0
Sources
- CVE-2002-1336 · CVE Program
- CVE-2002-1336 · NVD
- FIRST EPSS
- GHSA-fcjm-23wr-m9g6 · GitHub Advisory Database · CC BY 4.0
- CVE-2002-1336 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences