How severe is CVE-2026-2646?

CVE-2026-2646 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-2646 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-2646?

CVE-2026-2646 affects Wolfssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-2646?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-2646 have an EU (EUVD) identifier?

Yes. CVE-2026-2646 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13137.

When was CVE-2026-2646 published?

CVE-2026-2646 was published on 2026-03-19 and last updated on 2026-06-17.

CVE-2026-2646

CVE-2026-2646 is a high-severity vulnerability in Wolfssl with a CVSS 3.x base score of 8.1. 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-787.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v4: 5.0
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13137
Weakness: CWE-787
Affected product: Wolfssl
Published: 2026-03-19
Last modified: 2026-06-17

Description

A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function. When deserializing session data with SESSION_CERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and corrupt heap memory. A maliciously crafted session would need to be loaded from an external source to trigger this vulnerability. Internal sessions were not vulnerable.

Frequently asked questions

What is CVE-2026-2646?: A heap-buffer-overflow vulnerability exists in wolfSSL's wolfSSL_d2i_SSL_SESSION() function. When deserializing session data with SESSION_CERTS enabled, certificate and session id lengths are read from an untrusted input without bounds validation, allowing an attacker to overflow fixed-size buffers and corrupt heap memory. A maliciously crafted session would need to be loaded from an external source to trigger this vulnerability. Internal sessions were not vulnerable.
How severe is CVE-2026-2646?: CVE-2026-2646 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-2646 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-2646?: CVE-2026-2646 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-2646?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-2646 have an EU (EUVD) identifier?: Yes. CVE-2026-2646 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13137.
When was CVE-2026-2646 published?: CVE-2026-2646 was published on 2026-03-19 and last updated on 2026-06-17.

References

Affected products (1)

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

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