CVE-2026-5393

OOB Read in DoTls13CertificateVerify with WOLFSSL_DUAL_ALG_CERTS

6.3 MediumFix available

Dual-Algorithm CertificateVerify out-of-bounds read. When processing a dual-algorithm CertificateVerify message, an out-of-bounds read can occur on crafted input. This can only occur when --enable-experimental and --enable-dual-alg-certs is used when building wolfSSL.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: Low
Availability: Low

Exploit likelihood

0.20%Up 0.2 points since Apr 10, 2026

What each source reports

CVE List Score used 6.3

OOB Read in DoTls13CertificateVerify with WOLFSSL_DUAL_ALG_CERTS

Record: CVE-2026-5393
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Weakness: CWE-125
Updated: 2026-11-02

EUVDEUVD-2026-21231 6.3

Record: EUVD-2026-21231
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-f4w6-5m9p-28hw 6.3

Dual-Algorithm CertificateVerify out-of-bounds read. When processing a dual-algorithm...

Record: GHSA-f4w6-5m9p-28hw
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness: CWE-125
Updated: 2026-11-02

NVD 6.3

Record: CVE-2026-5393
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness: CWE-125
Updated: 2026-11-02

OSV 6.3

OOB Read in DoTls13CertificateVerify with WOLFSSL_DUAL_ALG_CERTS

Record: CVE-2026-5393
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Weakness: CWE-125
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-5393 9.1

Record: DEBIAN-CVE-2026-5393
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Updated: 2026-11-02

OSVJLSEC-2026-721 6.3

Dual-Algorithm CertificateVerify out-of-bounds read

Record: JLSEC-2026-721
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-5393 6.3

Record: UBUNTU-CVE-2026-5393
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
CVSS 3.1: 9.1 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Updated: 2026-11-02

Affected products

wolfssl

Affected packages

Affected packages
Package	Affected	Fixed
`wolfssl` Debian:12	All versions, plus listed versions 5.5.4-25.5.4-2+deb12u15.5.4-2+deb12u25.5.4-2+deb12u35.5.4-2.1 Show 22 moreShow less 5.6.4-15.6.4-25.6.6-15.6.6-1.15.6.6-1.25.6.6-1.35.6.6-1.3~exp15.7.0-0.15.7.0-0.25.7.0-0.35.7.2-0.15.7.2-0.25.7.2-0.35.7.2-0.45.8.2-15.8.2-1.15.8.2-1.25.8.4-15.9.0-0.15.9.0-0.25.9.1-0.15.9.2-1	None known
`wolfssl` Debian:13	All versions, plus listed versions 5.7.2-0.15.7.2-0.1+deb13u15.7.2-0.1+deb13u25.7.2-0.25.7.2-0.3 Show 9 moreShow less 5.7.2-0.45.8.2-15.8.2-1.15.8.2-1.25.8.4-15.9.0-0.15.9.0-0.25.9.1-0.15.9.2-1	None known
`wolfSSL_jll` Julia	before 5.9.2+0	5.9.2+0
`wolfssl` Ubuntu:16.04:LTS	All versions, plus listed versions 3.4.8+dfsg-1	None known
`wolfssl` Ubuntu:18.04:LTS	All versions, plus listed versions 3.10.2+dfsg-23.12.0+dfsg-13.12.2+dfsg-13.13.0+dfsg-1	None known
`wolfssl` Ubuntu:20.04:LTS	All versions, plus listed versions 4.1.0+dfsg-24.2.0+dfsg-14.2.0+dfsg-24.2.0+dfsg-34.3.0+dfsg-2	None known
`wolfssl` Ubuntu:22.04:LTS	All versions, plus listed versions 4.6.0-35.0.0-15.1.1-15.2.0-15.2.0-2	None known
`wolfssl` Ubuntu:24.04:LTS	All versions, plus listed versions 5.5.4-25.5.4-2.15.6.4-25.6.6-1.25.6.6-1.35.6.6-1.3build1	None known
`wolfssl` Ubuntu:25.10	All versions, plus listed versions 5.7.2-0.1	None known
`wolfssl` Ubuntu:26.10	All versions, plus listed versions 5.9.1-0.15.9.2-1	None known
`wolfssl` Ubuntu:26.04:LTS	All versions, plus listed versions 5.7.2-0.15.8.2-1.25.8.4-15.9.1-0.1	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-5393 is a medium vulnerability (CVSS 6.3) in Wolfssl, published April 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.20%, the 10th percentile. Fixed in wolfSSL_jll 5.9.2+0.