Command Injection in net-imap (CVE-2026-47242)
Summary
Command injection in net-imap (CVE-2026-47242). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 0.5.15 or later.
Original description
The description as published by the source.
Summary
Two Net::IMAP commands, #id and #enable, do not validate their arguments. Arguments to either command could be used by an attacker to inject arbitrary IMAP commands.
Please note that passing untrusted inputs to these commands is usually inappropriate and expected to be uncommon.
Details
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.
Impact
This is expected to impact very few users: use of untrusted user input for either command is expected to be very uncommon.
The documentation for #enable explicitly warns that using any arguments that are not in the explicitly supported list may result in undocumented behavior. Using arbitrary untrusted user input for #enable will always be inappropriate.
Although client ID field values will most commonly be static and hardcoded, dynamic input sources may be used. For example, client ID fields may be set by configuration or version numbers. Using untrusted user inputs for client ID fields is expected to be uncommon. But any untrusted inputs to client ID can trivially exploit this vulnerability.
Untrusted inputs to either command may include a CRLF sequence followed by a new IMAP command…
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-47242 has been found in net-imap.
Risk of unauthorized operations or information disclosure.
What to do: upgrade net-imap to 0.5.15 or later.
If unsure, ask your IT team or search "net-imap CVE-2026-47242" on the vendor's site.
CVE-2026-47242 (net-imap) — CWE-77
Patched: 0.5.15 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-77) exists in net-imap.
Check the vendor advisory for the affected versions of net-imap.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 0.5.15.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'net-imap' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'net-imap' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
net-imapを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade net-imap to 0.5.15ステージング環境で 0.5.15 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-47242 ruby-net-imap Fixed in: 0.5.15-r0
- Debian DEBIAN-CVE-2026-47242 ruby3.1
- Ubuntu UBUNTU-CVE-2026-47242 jruby
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web cve.org