Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, when Net::IMAP#id is called with a hash argument, although the ID field value strings are correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF sequences. While Net::IMAP#enable does process its arguments for aliases, it does not validate them as valid atoms (or as a list of valid atoms). The #to_s value is sent verbatim. Arguments to either command could be used by an attacker to inject arbitrary IMAP commands. This vulnerability is fixed in 0.6.5 and 0.5.15.
CVE-2026-47242
MEDIUMPre-NVD 5.85.8—
EchelonGraph scoreMEDIUM confidence
This medium-severity CVE scores 5.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 97% 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).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.8Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.8
- EG Score
- 5.8(medium)
- EPSS
- 3.1%
- KEV
- Not listed
Published
June 9, 2026
Last Modified
June 23, 2026
Advisory Details (1)
Auto-updated Jun 23, 2026Patch available. Sources: github.
github Patch Available
Command Injection via unvalidated ID and ENABLE arguments · Advisory · ruby/net-imap · GitHub
https://github.com/ruby/net-imap/security/advisories/GHSA-46q3-7gv7-qmggVendor Advisories for CVE-2026-47242(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Frequently asked(5)
What is CVE-2026-47242?
CVE-2026-47242 is a medium vulnerability published on June 9, 2026. Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality in Ruby. Prior to 0.6.5 and 0.5.15, when Net::IMAP#id is called with a hash argument, although the ID field value strings are correctly quoted (escaping quoted specials), they were not validated to prohibit CRLF…
When was CVE-2026-47242 disclosed?
CVE-2026-47242 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on June 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47242 actively exploited?
CVE-2026-47242 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-47242?
CVE-2026-47242 has a CVSS v3 base score of 5.8 (NVD).
How do I remediate CVE-2026-47242?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47242, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-47242
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