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TI-2026-04599 Aliases CVE-2026-5264GHSA-w5qh-hw7x-9w39

DTLS 1.3 ACK heap buffer overflow

Priority MEDIUM 44CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Heap buffer overflow in DTLS 1.3 ACK message processing. A remote attacker can send a crafted DTLS 1.3 ACK message that triggers a heap buffer overflow.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00454 39th percentileScored 2026-11-07
Fix Fixed wolfSSL (wolfSSL): 5.9.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
wolfSSLwolfSSLbefore 5.9.15.9.1Patch availableCNA
  • wolfSSL VendorwolfSSL Affected before 5.9.1 Fixed in 5.9.1 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*before 5.9.1VulnerablewolfSSL
  • cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:* Versions before 5.9.1 Vulnerable ·wolfSSL

Remediation

  • Fix · CNA wolfSSL (wolfSSL) Fixed in 5.9.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    wolfSSL 5.9.1

    10 records Highest priority Priority MEDIUM 2 MEDIUM, 8 LOW

    Other records, highest priority first

    • TI-2026-04537 wolfSSL ECDSA Certificate VerificationPriority MEDIUM 43
    • TI-2026-04782 Heap Use-After-Free in PQC Hybrid KeyShare Error Cleanup in wolfSSL TLS 1.3Priority LOW 33
    • TI-2026-04720 OOB Read in DoTls13CertificateVerify with WOLFSSL_DUAL_ALG_CERTSPriority LOW 33
    Show all 10 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-5264
  2. 2026-10-03 Alias added: GHSA-w5qh-hw7x-9w39

References

Patch 1

  • TI-2024-00830 SEGV and out of bounds memory read from malicious packet CVSS 3.1CRITICAL 9.1
  • TI-2022-18557 In wolfSSL before 5.5.1, malicious clients can cause a buffer overflow during a TLS 1.3… CVSS 3.1HIGH 7.5
  • TI-2025-10943 Potential DoS Vulnerability through Multiple KeyShareEntry with Same Group in TLS 1.3 ClientHello CVSS 4.0MEDIUM 6.3
  • TI-2017-09737 wolfSSL Bleichenbacher/ROBOT CVSS 3.0HIGH 7.5
  • TI-2019-08902 wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity… CVSS 3.1CRITICAL 9.8
  • TI-2017-02021 Improper certificate validation in wolfSSL CVSS 3.1CRITICAL 9.8
See all 150 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences