Vulnerability · Published Nov 26, 2025 · Assigned by mitre
CVE-2025-45311
High 8.8
In plain English
A high-severity security flaw in the fail2ban package (Debian). Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).
Severity (CVSS 3.1)8.8High
Exploit odds (30 days)0.4%top 66.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
Insecure permissions in fail2ban-client v0.11.2 allows attackers with limited sudo privileges to perform arbitrary operations as root. NOTE: this is disputed by multiple parties because the action for a triggered rule can legitimately be an arbitrary operation as root. Thus, the software is behaving in accordance with its intended privilege model.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | fail2ban | no fix listed | DEBIAN-CVE-2025-45311 |
| Debian:13 | fail2ban | no fix listed | DEBIAN-CVE-2025-45311 |
| Debian:14 | fail2ban | no fix listed | DEBIAN-CVE-2025-45311 |
Affected products (as reported)
Weakness: CWE-266 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H