syslink Avantra up to 25.3.0 on Linux/Windows session expiration

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, has been found in syslink Avantra up to 25.3.0 on Linux/Windows. This affects an unknown part. This manipulation causes session expiration. This vulnerability is handled as CVE-2026-8670. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in syslink Avantra up to 25.3.0 on Linux/Windows. It has been declared as critical. Affected by this vulnerability is an unknown functionality. The manipulation with an unknown input leads to a session expiration vulnerability. The CWE definition for the vulnerability is CWE-613. According to WASC, "Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization." As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at support.avantra.com. This vulnerability is known as CVE-2026-8670 since 05/15/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 25.3.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-31435). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.8

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.6
CNA Vector (NCSC.ch): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Session expiration
CWE: CWE-613
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Avantra 25.3.1

Timelineinfo

05/15/2026 CVE reserved
05/22/2026 +7 days Advisory disclosed
05/22/2026 +0 days VulDB entry created
05/22/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: support.avantra.com
Status: Confirmed

CVE: CVE-2026-8670 (🔒)
GCVE (CVE): GCVE-0-2026-8670
GCVE (VulDB): GCVE-100-365191
EUVD: 🔒

Entryinfo

Created: 05/22/2026 15:56
Updated: 05/22/2026 18:43
Changes: 05/22/2026 15:56 (63), 05/22/2026 18:43 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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