// For flags

CVE-2025-11931

Integer Underflow Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt

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 Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt. This issue is hit specifically with a call to the function wc_XChaCha20Poly1305_Decrypt() which is not used with TLS connections, only from direct calls from an application.

*Credits: Luigino Camastra from Aisle Research
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
Active
System
Vulnerable | Subsequent
Confidentiality
Low
Low
Integrity
Low
Low
Availability
None
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2025-10-17 CVE Reserved
  • 2025-11-21 CVE Published
  • 2025-12-08 CVE Updated
  • 2026-05-01 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/9223
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"
 < 5.8.4
Search vendor "WolfSSL" for product "WolfSSL" and version " < 5.8.4"
en
Affected