p PatchFirst

CVE-2026-3849

CVE-2026-3849 · Buffer Overflow in HPKE via Oversized ECH Config

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Stack Buffer Overflow in wc_HpkeLabeledExtract via Oversized ECH Config. A vulnerability existed in wolfSSL 5.8.4 ECH (Encrypted Client Hello) support, where a maliciously crafted ECH config could cause a stack buffer overflow on the client side, leading to potential remote execution and client program crash. This could be exploited by a malicious TLS server supporting ECH. Note that ECH is off by default, and is only enabled with enable-ech.

CVSS 6.9 · Medium · EPSS 0.5%

Published
Updated

Stack: system

Affected products and versions

  • wolfssl

    Versions
    • ≥ v5.6.0-stable, ≤ v5.8.4-stable: Affected (git)

    No fix published

  • wolfssl Debian:12

    Versions
    • 5.5.4-2
    • 5.5.4-2+deb12u1
    • 5.5.4-2+deb12u2
    • 5.5.4-2+deb12u3
    • 5.5.4-2.1
    • 5.6.4-1
    • 5.6.4-2
    • 5.6.6-1
    • 5.6.6-1.1
    • 5.6.6-1.2
    • 5.6.6-1.3
    • 5.6.6-1.3~exp1
    • 5.7.0-0.1
    • 5.7.0-0.2
    • 5.7.0-0.3
    • 5.7.2-0.1
    • 5.7.2-0.2
    • 5.7.2-0.3
    • 5.7.2-0.4
    • 5.8.2-1
    • 5.8.2-1.1
    • 5.8.2-1.2
    • 5.8.4-1
    • 5.9.0-0.1
    • 5.9.0-0.2
    • 5.9.1-0.1
    • 5.9.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Debian:13

    Versions
    • 5.7.2-0.1
    • 5.7.2-0.1+deb13u1
    • 5.7.2-0.1+deb13u2
    • 5.7.2-0.2
    • 5.7.2-0.3
    • 5.7.2-0.4
    • 5.8.2-1
    • 5.8.2-1.1
    • 5.8.2-1.2
    • 5.8.4-1
    • 5.9.0-0.1
    • 5.9.0-0.2
    • 5.9.1-0.1
    • 5.9.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:16.04:LTS

    Versions
    • 3.4.8+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:18.04:LTS

    Versions
    • 3.10.2+dfsg-2
    • 3.12.0+dfsg-1
    • 3.12.2+dfsg-1
    • 3.13.0+dfsg-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:20.04:LTS

    Versions
    • 4.1.0+dfsg-2
    • 4.2.0+dfsg-1
    • 4.2.0+dfsg-2
    • 4.2.0+dfsg-3
    • 4.3.0+dfsg-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:22.04:LTS

    Versions
    • 4.6.0-3
    • 5.0.0-1
    • 5.1.1-1
    • 5.2.0-1
    • 5.2.0-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:24.04:LTS

    Versions
    • 5.5.4-2
    • 5.5.4-2.1
    • 5.6.4-2
    • 5.6.6-1.2
    • 5.6.6-1.3
    • 5.6.6-1.3build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:25.10

    Versions
    • 5.7.2-0.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:26.10

    Versions
    • 5.9.1-0.1
    • 5.9.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • wolfssl Ubuntu:26.04:LTS

    Versions
    • 5.7.2-0.1
    • 5.8.2-1.2
    • 5.8.4-1
    • 5.9.1-0.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

Check your server →