Resource exhaustion in Ruby Net-Imap
CVE-2025-25186
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Starting in version 0.3.2 and prior to versions 0.3.8, 0.4.19, and 0.5.6, there is a possibility for denial of service by memory exhaustion in `net-imap`'s response parser. At any time while the client is connected, a malicious server can send can send highly compressed `uid-set` data which is automatically read by the client's receiver thread. The response parser uses `Range#to_a` to convert the `uid-set` data into arrays of integers, with no limitation on the expanded size of the ranges. Versions 0.3.8, 0.4.19, 0.5.6, and higher fix this issue. Additional details for proper configuration of fixed versions and backward compatibility are available in the GitHub Security Advisory.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.006 (47.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
Affected products
- Ruby Net-imap — versions >= 0.3.2, < 0.3.8, >= 0.4.0, < 0.4.19, >= 0.5.0, < 0.5.6
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-25186?
- CVE-2025-25186 is a medium-severity vulnerability in Ruby Net-Imap, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2025-02-10.
- How severe is CVE-2025-25186?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2025-25186 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.