CVE catalog
CVE-2023-6936
wolfssl: CVE-2023-6936
- Severity
- Medium
- Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.60% · Oct 25, 2026
In wolfSSL prior to 5.6.6, if callback functions are enabled (via the WOLFSSL_CALLBACKS flag), then a malicious TLS client or network attacker can trigger a buffer over-read on the heap of 5 bytes (WOLFSSL_CALLBACKS is only intended for debugging).
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | wolfssl | sid | 5.9.2-1.2 | fixed |
| Debian | wolfssl | trixie | 5.7.2-0.1+deb13u2 | fixed |
| Debian | wolfssl | bookworm | 5.5.4-2+deb12u2 | vulnerable |
| Debian | wolfssl | bookworm-security | 5.5.4-2+deb12u3 | vulnerable |
| Ubuntu | wolfssl | 16.04 | 3.4.8+dfsg-1 | vulnerable |
| Ubuntu | wolfssl | 18.04 | 3.10.2+dfsg-2 | vulnerable |
| Ubuntu | wolfssl | 18.04 | 3.12.0+dfsg-1 | vulnerable |
| Ubuntu | wolfssl | 18.04 | 3.12.2+dfsg-1 | vulnerable |
| Ubuntu | wolfssl | 18.04 | 3.13.0+dfsg-1 | vulnerable |
| Ubuntu | wolfssl | 20.04 | 4.1.0+dfsg-2 | vulnerable |
| Ubuntu | wolfssl | 20.04 | 4.2.0+dfsg-1 | vulnerable |
| Ubuntu | wolfssl | 20.04 | 4.2.0+dfsg-2 | vulnerable |
| Ubuntu | wolfssl | 20.04 | 4.2.0+dfsg-3 | vulnerable |
| Ubuntu | wolfssl | 20.04 | 4.3.0+dfsg-2 | vulnerable |
| Ubuntu | wolfssl | 22.04 | 4.6.0-3 | vulnerable |
| Ubuntu | wolfssl | 22.04 | 5.0.0-1 | vulnerable |
| Ubuntu | wolfssl | 22.04 | 5.1.1-1 | vulnerable |
| Ubuntu | wolfssl | 22.04 | 5.2.0-1 | vulnerable |
| Ubuntu | wolfssl | 22.04 | 5.2.0-2 | vulnerable |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | wolfssl | source | sid | 5.6.6-1.2 | not yet assigned | Not reported | [1059357] |
| Debian | wolfssl | source | trixie | 5.6.6-1.2 | not yet assigned | Not reported | [1059357] |
| Debian | wolfssl | source | bookworm | (unfixed) | not yet assigned | Not reported | [1059357] |
Notes
[bookworm] wolfssl: Minor issue
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.