CVE-2026-83540

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.55% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 45.8% of scored records. A rank, not a probability.

NVD base score

7.7 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-13.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-10-07 02:40Z22 DAYS AGO

Last updated

2026-10-07 11:29Z21 DAYS AGO

Reserved

2026-08-31

Assigning CNA

wolfSSL

Record state

PUBLISHED

Severity

High (CVSS 7.7)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-287Improper AuthenticationClass
• CWE-613Insufficient Session ExpirationBase

Data version

5.2

Document digest

4c0626410877c03c223b87464827b6bf7af269f049fc818c71efc8be1418db0f

• github.comwolfSSH source repositoryhttps://github.com/wolfSSL/wolfsshproduct
• github.comFix: give each Windows wolfSSHd connection its own authentication contexthttps://github.com/wolfSSL/wolfssh/commit/b6bd975ccfac6aadf29b98e35e09114bef3840a9patch
• github.comFix: add Windows sanity close of token before acquiring a new onehttps://github.com/wolfSSL/wolfssh/commit/9777bc5ce810d6c418a1473e9e8c40cdb0026e5apatch
• www.wolfssl.comwolfSSL security vulnerabilities pagehttps://www.wolfssl.com/docs/security-vulnerabilities/vendor-advisory