8.2

CVE-2025-11931: Integer Underflow Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt

Analyzed
AliasesUBUNTU-CVE-2025-11931DEBIAN-CVE-2025-11931ALPINE-CVE-2025-11931
Published 21-11-2025Last modified 08-12-2025

Vulnerability summary

CVE-2025-11931 is a high (CVSS 8.2) Integer Underflow (Wrap or Wraparound) vulnerability in wolfssl. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 27.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 2.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
8.2/10
010
High · v3.1 (NVD)
EPSS score
0.34%
0%100%
Low · +0.02 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 21-11-2025
    PublishedVulnerability first disclosed.
  2. 08-12-2025
    Last modifiedVulnerability information updated.

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 metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.34%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

Increase +0.02 pp

From 0.32% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine1 product
  • wolfssl< 5.9.1-r0 | < 5.8.4-r0
Debian1 product
  • wolfsslAll versions (No fix recorded)
Ubuntu1 product
  • wolfsslAll versions (No fix recorded)
Wolfssl1 product

4 vendors · 4 products

References

5 links