PT-2026-26349 · Wolfssl · Wolfssl

Haruto Kimura · CVE-2026-3849 · Published 2026-03-19 · Updated 2026-07-14

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions wolfSSL version 5.8.4

Description A flaw exists in wolfSSL 5.8.4’s Encrypted Client Hello (ECH) support. A specially crafted ECH configuration from a malicious TLS server can trigger a stack buffer overflow on the client side. This could potentially lead to remote code execution or a client program crash. ECH is disabled by default and requires explicit enabling. The vulnerable function is wc HpkeLabeledExtract.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Memory Corruption

Weakness Enumeration

CWE-787

Related Identifiers

CVE-2026-3849

JLSEC-2026-711

Affected Products

Wolfssl

References · 14

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/3xxx/CVE-2026-3849.json · Exploit
• https://github.com/wolfSSL/wolfssl/pull/9737 · Patch
• https://osv.dev/vulnerability/CVE-2026-3849 · Vendor Advisory
• https://osv.dev/vulnerability/JLSEC-2026-711 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-3849 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2026-3849 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-3849 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-3849 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-3849 · Security Note
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-3849 · Vendor Advisory
• https://twitter.com/harutosec/status/2072813379476209988 · Twitter Post
• https://twitter.com/CVEnew/status/2035992547609268426 · Twitter Post
• https://twitter.com/infoflowcloud/status/2035993985139823080 · Twitter Post
• https://github.com/advisories/GHSA-267h-vrw9-53p3 · Note