If a TLS 1.3 client gets neither a PSK (pre shared key) extension nor a KSE (key share extension) when connecting to a malicious server, a default predictable buffer gets used for the IKM (Input Keying Material) value when generating the session master secret. Using a potentially known IKM value when generating the session master secret key compromises the key generated, allowing an eavesdropper to reconstruct it and potentially allowing access to or meddling with message contents in the session. This issue does not affect client validation of connected servers, nor expose private key information, but could result in an insecure TLS 1.3 session when not controlling both sides of the connection. wolfSSL recommends that TLS 1.3 client side users update the version of wolfSSL used.
Conclusion & alert: CVE-2023-3724 is rated Moderate Risk (51.2/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.54%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.08% | 0.54% | +0.46% |
| 2 | 2025-11-21 | 0.36% | 0.08% | -0.27% |
| 3 | 2025-11-18 | — | 0.36% | — |
Full EPSS history (12 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.1 | 3.1 | CRITICAL |
|
2.3 | 6.0 | [email protected] |
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
high | CVE-2023-3724: 1 source package rows (wolfssl); 14 state rows across 6 repos (3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 6, open 8. | https://security.alpinelinux.org/vuln/CVE-2023-3724 |
debian
|
not yet assigned | CVE-2023-3724 not yet assigned priority: Debian including 1 source packages (wolfssl), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. | https://security-tracker.debian.org/tracker/CVE-2023-3724 |
ubuntu
|
medium | CVE-2023-3724 medium priority: Ubuntu including 1 source packages (wolfssl), 13 status rows across 13 suites (bionic, focal, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 7, ignored 6. | https://ubuntu.com/security/CVE-2023-3724 |
| URL | Tags |
|---|---|
| https://github.com/wolfSSL/wolfssl/pull/6412 | Patch |
| https://www.wolfssl.com/docs/security-vulnerabilities/ | Vendor Advisory |