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.
Affected products
ruby-lang: net\
References7
- github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw MitigationVendor Advisory
- github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d… Patch
- github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75… Patch
- github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8a… Patch
- github.com/ruby/net-imap/releases/tag/v0.4.24 Release Notes
- github.com/ruby/net-imap/releases/tag/v0.5.14 Release Notes
- github.com/ruby/net-imap/releases/tag/v0.6.4 Release Notes
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 4.0
-
2.3
LOW
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 36 · as of 14 November 2026
- CWE
- CWE-407
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.