Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Affects Red HatSource GCVE Database
Not known to be exploited.
Data as of 3 Nov 2026, 04:46 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.
What to do
AI-suggested
Red Hat has released updated RPM packages for nghttp2 in their Hardened Images to fix this vulnerability. Users should apply these updates as provided by Red Hat. Additionally, configuring web application firewalls or load balancers to drop incoming HTTP/1.1 requests containing both Upgrade and Content-Length headers can block malformed traffic at the network edge before it reaches the vulnerable proxy, mitigating the risk without affecting legitimate traffic.
Description
A security flaw in the nghttp2 nghttpx proxy allows remote attackers to perform HTTP request smuggling and cross-client response-queue poisoning. This occurs due to ambiguous forwarding of HTTP/1.1 Upgrade requests containing a Content-Length header to reusable keep-alive backend connections. The vulnerability requires high attack complexity to exploit successfully on the backend server. A security update addressing this issue is available in Red Hat Hardened Images RPMs.
References
- access.redhat.com/errata/RHSA-2026:52414 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-58055 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- images.redhat.com (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_52414.json (opens in a new tab)