CVE-2026-90678VulnerabilityPublished 27 Aug 2026Updated 6 Nov 2026

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Affects Red HatSource GCVE Database

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Not known to be exploited.

Data as of 6 Nov 2026, 03:02 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

Exploitation evidence

Disclosed: evidence found.
CVE published 27 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 5 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

Red Hat recommends avoiding configuring HAProxy with a QUIC bind listener and HTTP/3 frontend unless strictly necessary. If HTTP/3 functionality is required, review HAProxy configurations to prevent backend connection reuse and avoid using chunked transfer encoding over HTTP/1.1 for traffic susceptible to this vulnerability. Updated packages including haproxy-3.0.27-0.1.hum1 are available as part of Red Hat Hardened Images RPMs and should be applied to remediate the issue.

Description

A vulnerability in HAProxy's HTTP/3 multiplexer allows remote unauthenticated attackers to perform HTTP request smuggling when HAProxy is configured with QUIC support and an HTTP/3 frontend, routing traffic to an HTTP/1.1 backend using chunked transfer coding on reused connections. This flaw can bypass frontend security rules and potentially expose sensitive client data such as authentication credentials. The issue is addressed in updated Red Hat Hardened Images RPMs including haproxy-3.0.27-0.1.hum1. Mitigation includes avoiding the use of QUIC bind listener and HTTP/3 frontend if not required, or reviewing configurations to prevent backend connection reuse or chunked transfer encoding over HTTP/1.1.

Impact

Successful exploitation of this vulnerability allows remote unauthenticated attackers to bypass frontend security rules and potentially intercept or cause loss of other clients' HTTP requests, including sensitive information such as authentication credentials. This can lead to unauthorized access and compromise of client data. The impact is rated high by Red Hat, with confidentiality and integrity impacts considered high and availability impact low.

CWE-444Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling) (opens in a new tab)
Base weaknessOWASP Top 10 A06:2025: Insecure Design (opens in a new tab)
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
Implementation
Use a web server that employs a strict HTTP parsing procedure, such as Apache.
Implementation
Use only SSL communication.
Implementation
Terminate the client session after each request.
OWASP Cheat Sheets
REST Assessment (opens in a new tab)
REST Security (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Secure Design Principles (opens in a new tab)
OWASP ASVS 4.0.3
V13.2.5 (opens in a new tab)
Attack patterns
HTTP Response Smuggling (opens in a new tab)
HTTP Request Smuggling (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 6 Nov 2026, 03:02 UTC

WeaknessesCWE-444

Technical details

References

Community reviews

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