CVE-2026-8670
This vulnerability allows attackers to reuse session IDs in Syslink Software AG Avantra on Linux and Windows, enabling session replay attacks. It affects versions before 25.3.1 and can lead to unauthorized access and full compromise of confidentiality, integrity, and availability.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Syslink Software AG Avantra on Linux and Windows, versions prior to 25.3.1.
Real-world impact
An attacker who can observe or capture a valid session ID can replay it to gain unauthorized access to the system, potentially taking full control of the affected application.
Why this severity
The CVSS score of 9.6 reflects that the flaw can be exploited remotely over the network with no special privileges, requires user interaction, and can compromise confidentiality, integrity, and availability. The high impact and low attack complexity drive the critical rating.
What to do about it
- 01Upgrade Avantra to version 25.3.1 or later.
NVD description
Timeline
- May 22, 2026 · May 22, 2026PublishedDisclosed and added to the National Vulnerability Database.
- Jul 23, 2026 · 12d agoAdvisory updatedThe NVD record was last revised.
- Jul 25, 2026 · 10d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
How it’s attacked
References & advisories
- support.avantra.com/hc/en-us/articles/553392991…mitigationvendor advisory