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.
CVE-2026-42245
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 66% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- 34(Track)EG Risk 34/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 34%
- KEV
- Not listed
Published
May 9, 2026
Last Modified
July 24, 2026
Advisory Details (7)
Auto-updated May 18, 2026Quadratic complexity when reading response literals · Advisory · ruby/net-imap · GitHub
https://github.com/ruby/net-imap/security/advisories/GHSA-q2mw-fvj9-vvcwRelease v0.5.14 · ruby/net-imap · GitHub
https://github.com/ruby/net-imap/releases/tag/v0.5.14Release v0.4.24 · ruby/net-imap · GitHub
https://github.com/ruby/net-imap/releases/tag/v0.4.24🔀 Merge pull request #642 from ruby/response_reader-performance · ruby/net-imap@de685f9 · GitHub
https://github.com/ruby/net-imap/commit/de685f91a4a4cc75eb80da898c2bf8af08d34819🔀 Merge pull request #651 from ruby/backport/v0.4/response_reader-non… · ruby/net-imap@88d9523 · GitHub
https://github.com/ruby/net-imap/commit/88d95231fc8afef11c1f074453f7d75b68c9dfda🔀 Merge pull request #650 from ruby/backport/v0.5/response_reader-non… · ruby/net-imap@6091f7d · GitHub
https://github.com/ruby/net-imap/commit/6091f7d6b1f3514cafbfe39c76f2b5d73de3ca96Vendor Advisories for CVE-2026-42245(12)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:38694Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:37238Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:3.3 security update
- RHSA-2026:36099Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:3.3 security update
- RHSA-2026:35895Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby security update
- RHSA-2026:33721Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:33577Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:4.0 security update
- RHSA-2026:33576Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:3.3 security update
- RHSA-2026:33515Red Hat Product SecurityHigh
Red Hat Security Advisory: ruby:3.3 security update
- +4 more
Patch Availability(12)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| redhat | ruby3-4-main-3.4.10-31.hum1 | 2026-07-13 | redhat |
| redhat | ruby:3.3-9060020260630075016.9 | 2026-07-09 | redhat |
| redhat | ruby:3.3-9040020260630065449.9 | 2026-07-07 | redhat |
| redhat | ruby-0:3.3.10-11.el10_0.2 | 2026-07-06 | redhat |
| redhat | ruby4-0-main-4.0.0-33.4.hum1 | 2026-06-30 | redhat |
| redhat | ruby4.0-0:4.0.3-35.el10_2 | 2026-06-30 | redhat |
| redhat | ruby:4.0-9080020260619130154.9 | 2026-06-30 | redhat |
| redhat | ruby-0:3.3.10-13.el10_2 | 2026-06-30 | redhat |
| redhat | ruby3-3-main-3.3.10-23.2.hum1 | 2026-06-30 | redhat |
| redhat | ruby:3.3-8100020260615131010.489197e6 | 2026-06-30 | redhat |
| redhat | ruby:3.3-9080020260615131001.9 | 2026-06-30 | redhat |
| redhat | ruby3-4-main-3.4.8-31.2.hum1 | 2026-06-30 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(5 across 5 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ruby2.7 | 2.7.4-1 ... 2.7.5-1 (8 versions) | — | — |
Debian:12(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ruby3.1 | 3.1.2-7 ... 3.1.2-8.5 (8 versions) | — | — |
Debian:13(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ruby3.3 | 3.3.8-2, 3.3.8-2.1, 3.3.8-2.2 | — | — |
Debian:14(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ruby3.3 | 3.3.8-2, 3.3.8-2.1, 3.3.8-2.2 | — | — |
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| net-imap | 0.1.0 ... 0.4.9.1 (45 versions) | 0.4.24 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 66× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 158 total refreshes for this CVE.
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-23 18:50 UTCEG score recompute
- 2026-08-23 18:50 UTCVendor advisory
- 2026-08-23 00:19 UTCEPSS rescore
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-20 22:55 UTCEPSS rescore
- 2026-08-19 17:03 UTCEPSS rescore
- 2026-08-18 13:48 UTCEPSS rescore
- 2026-08-17 13:47 UTCEPSS rescore
- 2026-08-17 11:27 UTCEG score recompute
- 2026-08-17 11:27 UTCVendor advisory
- 2026-08-16 14:56 UTCEPSS rescore
- 2026-08-16 04:30 UTCEG score recompute
- 2026-08-16 04:30 UTCVendor advisory
- 2026-08-16 02:14 UTCEPSS rescore
- 2026-08-15 02:07 UTCEG score recompute
- 2026-08-15 02:07 UTCVendor advisory
- 2026-08-15 01:30 UTCEPSS rescore
- 2026-08-14 14:36 UTCVendor advisory
- 2026-08-14 03:05 UTCEG score recompute
- 2026-08-14 03:05 UTCVendor advisory
- 2026-08-13 22:00 UTCEPSS rescore
- 2026-08-13 04:11 UTCVendor advisory
- 2026-08-12 16:40 UTCEG score recompute
- 2026-08-12 16:40 UTCVendor advisory
Show 75 moreShow fewer
- 2026-08-12 13:51 UTCEPSS rescore
- 2026-08-11 15:49 UTCEG score recompute
- 2026-08-11 15:49 UTCVendor advisory
- 2026-08-11 13:43 UTCEPSS rescore
- 2026-08-11 01:14 UTCEG score recompute
- 2026-08-11 01:14 UTCVendor advisory
- 2026-08-11 00:00 UTCEPSS rescore
- 2026-08-10 12:53 UTCVendor advisory
- 2026-08-10 01:23 UTCVendor advisory
- 2026-08-09 13:51 UTCEG score recompute
- 2026-08-09 13:51 UTCVendor advisory
- 2026-08-09 13:46 UTCEPSS rescore
- 2026-08-09 02:20 UTCEG score recompute
- 2026-08-09 02:20 UTCVendor advisory
- 2026-08-08 16:37 UTCEPSS rescore
- 2026-08-08 07:41 UTCVendor advisory
- 2026-08-07 20:10 UTCEG score recompute
- 2026-08-07 20:10 UTCVendor advisory
- 2026-08-07 08:39 UTCVendor advisory
- 2026-08-06 21:07 UTCEG score recompute
- 2026-08-06 21:07 UTCVendor advisory
- 2026-08-06 13:46 UTCEPSS rescore
- 2026-08-06 09:37 UTCVendor advisory
- 2026-08-05 22:05 UTCEG score recompute
- 2026-08-05 22:05 UTCVendor advisory
- 2026-08-05 19:17 UTCEPSS rescore
- 2026-08-04 15:10 UTCEPSS rescore
- 2026-08-04 10:38 UTCEPSS rescore
- 2026-08-03 19:28 UTCEG score recompute
- 2026-08-03 19:28 UTCVendor advisory
- 2026-08-03 10:36 UTCEPSS rescore
- 2026-08-03 01:39 UTCVendor advisory
- 2026-08-02 14:08 UTCVendor advisory
- 2026-08-02 02:37 UTCEG score recompute
- 2026-08-02 02:37 UTCVendor advisory
- 2026-08-02 02:27 UTCEPSS rescore
- 2026-08-01 04:16 UTCEPSS rescore
- 2026-07-30 16:28 UTCEPSS rescore
- 2026-07-30 01:30 UTCEPSS rescore
- 2026-07-28 15:36 UTCEPSS rescore
- 2026-07-27 14:13 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-26 08:25 UTCEG score recompute
- 2026-07-26 08:25 UTCVendor advisory
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:11 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-16 03:53 UTCOSV refresh
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-13 22:30 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:15 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:06 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
Frequently asked(5)
What is CVE-2026-42245?
When was CVE-2026-42245 disclosed?
Is CVE-2026-42245 actively exploited?
What is the CVSS score of CVE-2026-42245?
How do I remediate CVE-2026-42245?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-42245
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