CVE-2026-42245
CVE-2026-42245 — net-imap: Quadratic complexity when reading response literals
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.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
0%
chance of exploitation in 30 days
CVSS base
2.3
LOW
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 2.3 | CVSS 4.0 | LOW | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-407
References
7 on the record
- github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcw
x_refsource_CONFIRM
- github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca96
x_refsource_MISC
- github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda
x_refsource_MISC
- github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d34819
x_refsource_MISC
- github.com/ruby/net-imap/releases/tag/v0.4.24
x_refsource_MISC
- github.com/ruby/net-imap/releases/tag/v0.5.14
x_refsource_MISC
- github.com/ruby/net-imap/releases/tag/v0.6.4
x_refsource_MISC
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.