CVE-2026-42245
net-imap has quadratic complexity when reading response literals
7.5
HIGH
CVSS 3.1
EPSS 0.09%
Description
Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to versions 0.4.24, 0.5.14, and 0.6.4, Net::IMAP::ResponseReader has quadratic time complexity when reading large responses containing many string literals. A hostile server can send responses which are crafted to exhaust the client's CPU for a denial of service attack. This issue has been patched in versions 0.4.24, 0.5.14, and 0.6.4.
How to fix CVE-2026-42245
To remediate CVE-2026-42245, upgrade the affected package to a fixed version below.
- —no fix listed
- —no fix listed
- —no fix listed
- —upgrade to 0.6.4 or later
Is CVE-2026-42245 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0
- from 0
- from 0
- >= 0.6.0, < 0.6.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |