CVE-2026-5778CWE-191

Integer underflow leads to out-of-bounds access in sniffer ChaCha decrypt path.

Low · published April 9, 2026

CVSS v4.0
2.1
EPSS
0%
Percentile
30.0
In the wild
Unconfirmed
What it is

Integer underflow in wolfSSL packet sniffer <= 5.9.0 allows an attacker to cause a program crash in the AEAD decryption path by injecting a TLS record shorter than the explicit IV plus authentication tag into traffic inspected by ssl_DecodePacket. The underflow wraps a 16-bit length to a large value that is passed to AEAD decryption routines, causing a large out-of-bounds read and crash. An unauthenticated attacker can trigger this remotely via malformed TLS Application Data records.

The record
Technical detail
CVSS v4.0
2.1 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00372 · 30.0th percentile
Weakness
CWE-191 · Integer Underflow (Wrap or Wraparound)
Published
2026-04-09T21:45Z
EPSS history
Timeline
  • 09 APR 21:45Z
    Integer underflow leads to out-of-bounds access in sniffer ChaCha decrypt path.
    cvelistv5