Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
A denial of service vulnerability exists in the Net::IMAP Ruby library used in Red Hat Hardened Images. A malicious IMAP server can exploit a quadratic time complexity issue in the Net::IMAP::ResponseReader when processing large responses with many string literals, causing excessive CPU consumption and potential client process exhaustion. This vulnerability does not allow code execution, privilege escalation, or unauthorized data access. Red Hat rates this flaw as Moderate in severity and has released updated RPM packages to address it.
AI Analysis
Technical Summary
CVE-2026-42245 is a denial of service vulnerability in the Net::IMAP Ruby library, specifically in the ResponseReader component. The flaw arises from a quadratic time complexity when handling large IMAP server responses containing numerous string literals. A hostile IMAP server can exploit this to exhaust the CPU resources of the client application using the vulnerable library, leading to a denial of service condition. The vulnerability impacts Red Hat Hardened Images RPMs including ruby4.0 and related rubygem4.0 packages. Red Hat has released updated RPMs (version 4.0.0-33.4.hum1 and related) to fix this issue. Exploitation requires interaction with a malicious IMAP server, and the impact is limited to resource exhaustion without further compromise.
Potential Impact
Successful exploitation results in denial of service due to excessive CPU consumption in the affected client process using the Net::IMAP library. There is no impact on confidentiality, integrity, or privilege escalation. The availability impact is high for the affected client application but limited to resource exhaustion only.
Mitigation Recommendations
Red Hat has released updated RPM packages that fix this vulnerability. Users should apply the provided security update to ruby4.0 and associated rubygem4.0 packages as detailed in Red Hat Advisory RHSA-2026:33551. Additionally, to reduce risk, applications using the Net::IMAP library should be configured to connect only to trusted IMAP servers and avoid untrusted or unverified IMAP services, as exploitation requires interaction with a hostile server.
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Description
A denial of service vulnerability exists in the Net::IMAP Ruby library used in Red Hat Hardened Images. A malicious IMAP server can exploit a quadratic time complexity issue in the Net::IMAP::ResponseReader when processing large responses with many string literals, causing excessive CPU consumption and potential client process exhaustion. This vulnerability does not allow code execution, privilege escalation, or unauthorized data access. Red Hat rates this flaw as Moderate in severity and has released updated RPM packages to address it.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-42245 is a denial of service vulnerability in the Net::IMAP Ruby library, specifically in the ResponseReader component. The flaw arises from a quadratic time complexity when handling large IMAP server responses containing numerous string literals. A hostile IMAP server can exploit this to exhaust the CPU resources of the client application using the vulnerable library, leading to a denial of service condition. The vulnerability impacts Red Hat Hardened Images RPMs including ruby4.0 and related rubygem4.0 packages. Red Hat has released updated RPMs (version 4.0.0-33.4.hum1 and related) to fix this issue. Exploitation requires interaction with a malicious IMAP server, and the impact is limited to resource exhaustion without further compromise.
Potential Impact
Successful exploitation results in denial of service due to excessive CPU consumption in the affected client process using the Net::IMAP library. There is no impact on confidentiality, integrity, or privilege escalation. The availability impact is high for the affected client application but limited to resource exhaustion only.
Mitigation Recommendations
Red Hat has released updated RPM packages that fix this vulnerability. Users should apply the provided security update to ruby4.0 and associated rubygem4.0 packages as detailed in Red Hat Advisory RHSA-2026:33551. Additionally, to reduce risk, applications using the Net::IMAP library should be configured to connect only to trusted IMAP servers and avoid untrusted or unverified IMAP services, as exploitation requires interaction with a hostile server.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_security_advisory
- Csaf Version
- 2.0
- Publisher
- Red Hat Product Security
- Advisory Id
- RHSA-2026:33551
- Cve Count
- 3
- Additional Cves
- ["CVE-2026-42246","CVE-2026-42256"]
- Cvss Version
- null
Threat ID: 6a4452de27e9c797198e0950
Added to database: 06/30/2026, 23:35:58 UTC
Last enriched: 08/09/2026, 17:23:32 UTC
Last updated: 08/14/2026, 00:41:12 UTC
Views: 93
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