CVE-2026-27135VulnerabilityPublished 3 Jun 2026Updated 30 Oct 2026

Red Hat Security Advisory: OpenShift Container Platform 4.18.43 bug fix and security update

Affects Red HatSource GCVE Database

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Mentioned vulnerabilities

Not known to be exploited · fixed in Red Hat package updates : patch Red Hat soon.

Data as of 30 Oct 2026, 02:47 UTC

Severity

High

Rated by Threat Radar · No CVSS score from NVD or the CNA

Patch: Available – fixed in 4.18.43

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Jun 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 29 Oct 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

Users of Red Hat OpenShift Container Platform 4.18 should upgrade to version 4.18.43, which contains updated container images and packages that address these vulnerabilities. Upgrades can be performed via the OpenShift CLI (oc) or the web console. Refer to the official Red Hat documentation for detailed upgrade instructions. No additional mitigations are specified beyond applying the update.

Description

Red Hat OpenShift Container Platform 4.18.43 includes important security updates addressing multiple vulnerabilities: a denial of service in nghttp2 via malformed HTTP/2 frames (CVE-2026-27135), a privilege escalation in sudo due to failure in privilege drop calls (CVE-2026-35535), and a local privilege escalation in the Linux kernel related to the "Fragnesia" variant of the Dirty Frag vulnerability (CVE-2026-46300). Users of OpenShift Container Platform 4.18 are advised to upgrade to these updated packages and container images to mitigate these issues.

Impact

The vulnerabilities fixed in this update include denial of service, local privilege escalation, and privilege escalation issues. The nghttp2 flaw allows denial of service via malformed HTTP/2 frames. The sudo vulnerability enables privilege escalation due to improper privilege dropping. The kernel vulnerability allows local privilege escalation through a variant of the Dirty Frag vulnerability. These issues could allow attackers to disrupt service or gain elevated privileges on affected systems running OpenShift Container Platform 4.18 prior to 4.18.43.

CWE-617Reachable Assertion (opens in a new tab)
Base weakness
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
Implementation
If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
Implementation
Consider changing the assertion to some other less "fatal" error. This might not be easy to implement, since other code may be needed to handle the error.
Implementation
Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-272Least Privilege Violation (opens in a new tab)
Base weakness
The elevated privilege level required to perform operations such as chroot() should be dropped immediately after the operation is performed.
Architecture and Design · Operation
Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
Architecture and Design · Separation of Privilege
Follow the principle of least privilege when assigning access rights to entities in a software system.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
OWASP ASVS 4.0.3
V10.2.2 (opens in a new tab)
V1.4.4 (opens in a new tab)
V1.4.5 (opens in a new tab)
Attack patterns
Using Malicious Files (opens in a new tab)
Leverage Executable Code in Non-Executable Files (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-664Improper Control of a Resource Through its Lifetime (opens in a new tab)
Pillar weakness
The product does not maintain or incorrectly maintains control over a resource throughout its lifetime of creation, use, and release.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Attack patterns
Session Credential Falsification through Forging (opens in a new tab)
Reusing Session IDs (aka Session Replay) (opens in a new tab)
Session Fixation (opens in a new tab)
Cross Site Request Forgery (opens in a new tab)
Exploitation of Trusted Identifiers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-123Write-what-where Condition (opens in a new tab)
Base weaknessLikelihood of exploit: High
Any condition where the attacker has the ability to write an arbitrary value to an arbitrary location, often as the result of a buffer overflow.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
Operation
Use OS-level preventative functionality integrated after the fact. Not a complete solution.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 30 Oct 2026, 02:47 UTC

WeaknessesCWE-617, CWE-272, CWE-664 +1

Technical details

References

Community reviews

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