What is CVE-2026-8670?

CVE-2026-8670 is a critical-severity vulnerability in Avantra, classified under Insufficient Session Expiration. CVSS score: 9.6/10. Published 2026-05-22.

How severe is CVE-2026-8670?

Critical severity. CVSS v3 base score is 9.6 out of 10.

Vulnerability in Avantra

CVE-2026-8670

Insufficient session expiration vulnerability in syslink software AG Avantra on Linux, Windows allows Reusing Session IDs (aka Session Replay). This issue affects Avantra: before 25.3.1.

EPSS: 0.000 (14.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

Affected products

Avantra
Linux Linux_kernel
Microsoft Windows
Syslink Software Ag Avantra — versions 0

Weakness classification (CWE)

CWE-613 — Insufficient Session Expiration

References

vulnerability@ncsc.ch (vendor-advisory, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-8670?: CVE-2026-8670 is a critical-severity vulnerability in Avantra, classified under Insufficient Session Expiration. CVSS score: 9.6/10. Published 2026-05-22.
How severe is CVE-2026-8670?: Critical severity. CVSS v3 base score is 9.6 out of 10.