Low 2.3Published May 9, 2026

CVE-2026-42245net-imap: Quadratic complexity when reading response literals

Updated under an hour ago (Oct 27, 2026, 1:23 PM ET)

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It affects ruby net-imap and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for ruby net-imap

Exploited in the last 30 days

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.

CVSS: 2.3 LOW (v4.0, 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
Weakness (CWE): CWE-407
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: May 12, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

ruby net-imap ruby:net_imap (from the name)	before 0.4.24; from 0.5.0, < 0.5.14; from 0.6.0, < 0.6.4	CNA record
ruby-lang net::imap ruby-lang:net::imap	before 0.4.24; from 0.5.0 before 0.5.14; from 0.6.0 before 0.6.4	NVD

References

References

https://github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw	x-refsource-confirm, mitigation, vendor-advisory
https://github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca96	x-refsource-misc, patch
https://github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda	x-refsource-misc, patch
https://github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d34819	x-refsource-misc, patch
https://github.com/ruby/net-imap/releases/tag/v0.4.24	x-refsource-misc, release-notes
https://github.com/ruby/net-imap/releases/tag/v0.5.14	x-refsource-misc, release-notes
https://github.com/ruby/net-imap/releases/tag/v0.6.4	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.