High severity · published Nov 21, 2025
CVE-2025-11931
Integer Underflow Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt
8.2
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
wolfSSL · wolfSSL
before 5.8.4 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-11931
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-11931
Issue Tracking
https://github.com/wolfSSL/wolfssl/pull/9223
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