Cyber Resilience

CVE-2026-8673

Avantra ≤ 25.3.0

Published
22 May 2026
Modified
23 July 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0019 9th percentile
Risk Priority 43 floored blend · peak EPSS

Summary

CVE-2026-8673 is a medium-severity Unprotected Transport of Credentials (CWE-523) vulnerability in Avantra Avantra. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Sniffing (T1040); ranked at the 9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A04:2025 Cryptographic Failures

EU & UK References

Vulnerability Data

Unprotected transport of credentials vulnerability in syslink software AG Avantra on Linux, Windows allows Sniffing Attacks. This issue affects Avantra: before 25.3.0.

CWE(s)
CWE-523

Related Threats

MITRE ATT&CK Enterprise Techniques

T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-8670Same product: Avantra Avantra
CVE-2026-8672Same product: Avantra Avantra
CVE-2026-8671Same product: Avantra Avantra
CVE-2023-4509Same product: Linux Linux Kernel
CVE-2024-49387Same product: Linux Linux Kernel
CVE-2023-34142Same product: Linux Linux Kernel
CVE-2024-6972Same product: Linux Linux Kernel
CVE-2024-39746Same product: Linux Linux Kernel
CVE-2024-41763Same product: Linux Linux Kernel
CVE-2024-39745Same product: Linux Linux Kernel

Affected Assets

avantra
avantra
≤ 25.3.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

—

Mitigating Controls (NIST 800-53 r5) AI

SC-8 Transmission Confidentiality and Integrity good match

SC-8 requires confidentiality protection for transmitted data, directly stopping credentials from traveling in plaintext.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.DS-02 full match
prevents

Encryption of data-in-transit directly prevents exposure of credentials during login.

PR.AA-04 mostly match
prevents

Protecting identity assertions in transit covers credential transport but is narrower than the full control scope.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.24 Use of cryptography mostly match
prevents

Requires use of cryptography, directly enabling encryption of credentials in transit.

A.5.14 Information transfer partial match
prevents

Requires secure information transfer, which can include protecting credentials in transit.

A.5.17 Authentication information partial match
degrades

Addresses management of authentication information, indirectly supporting protection during transmission.

A.8.20 Networks security partial match
prevents

Requires network security controls that can protect credential transmission.

A.8.21 Security of network services partial match
prevents

Addresses security of network services, which may include protecting authentication traffic.

A.8.26 Application security requirements partial match
prevents

Specifies application security requirements that can include secure credential transmission.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (2 rules)
  • V-230487 RHEL 8 must not have the telnet-server package installed. prevents CWE-523
  • V-230492 RHEL 8 must not have the rsh-server package installed. prevents CWE-523

References