// For flags

CVE-2026-5778

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

Severity Score

2.1
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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.

*Credits: Zou Dikai
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
Low
User Interaction
Passive
System
Vulnerable | Subsequent
Confidentiality
None
None
Integrity
None
None
Availability
Low
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2026-04-08 CVE Reserved
  • 2026-04-09 CVE Published
  • 2026-04-13 CVE Updated
  • 2026-05-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-191: Integer Underflow (Wrap or Wraparound)
CAPEC
References (1)
URL Tag Source
https://github.com/wolfSSL/wolfssl/pull/10125
URL Date SRC
URL Date SRC
URL Date SRC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
WolfSSL
Search vendor "WolfSSL"
 WolfSSL
Search vendor "WolfSSL" for product "WolfSSL"
 <= 5.9.0
Search vendor "WolfSSL" for product "WolfSSL" and version " <= 5.9.0"
en
Affected