1-2 Byte Buffer Overflow in wolfSSL_X509_notAfter/notBefore
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
X.509 date buffer overflow in wolfSSL_X509_notAfter / wolfSSL_X509_notBefore. A buffer overflow may occur when parsing date fields from a crafted X.509 certificate via the compatibility layer API. This is only triggered when calling these two APIs directly from an application, and does not affect TLS or certificate verify operations in wolfSSL.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
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-2026-04599 DTLS 1.3 ACK heap buffer overflowPriority MEDIUM 44
- 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
Timeline
- 2026-10-02 Threatist record created from CVE-2026-5448
- 2026-10-03 Alias added: GHSA-5jqq-xpcr-q3r7
References
More Wolfssl vulnerabilities
- 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
Sources
- CVE-2026-5448 · CVE Program
- CVE-2026-5448 · NVD
- FIRST EPSS
- GHSA-5jqq-xpcr-q3r7 · GitHub Advisory Database · CC BY 4.0
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