How severe is CVE-2023-6936?

CVE-2023-6936 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-6936 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-6936?

CVE-2023-6936 affects Wolfssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-6936?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2023-6936 have an EU (EUVD) identifier?

Yes. CVE-2023-6936 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-59134.

When was CVE-2023-6936 published?

CVE-2023-6936 was published on 2024-02-20 and last updated on 2026-06-17.

CVE-2023-6936

CVE-2023-6936 is a medium-severity vulnerability in Wolfssl with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-59134
Weakness: CWE-125
Affected product: Wolfssl
Published: 2024-02-20
Last modified: 2026-06-17

Description

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).

Frequently asked questions

What is CVE-2023-6936?: 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).
How severe is CVE-2023-6936?: CVE-2023-6936 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-6936 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-6936?: CVE-2023-6936 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-6936?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2023-6936 have an EU (EUVD) identifier?: Yes. CVE-2023-6936 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-59134.
When was CVE-2023-6936 published?: CVE-2023-6936 was published on 2024-02-20 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

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