CVE-2026-84375VulnerabilityPublished 11 Nov 2026Updated 13 Nov 2026

Red Hat Security Advisory: OpenShift Virtualization v4.20 Images

Affects Red HatSource GCVE Database

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Authoritative record:CVE-2026-84375· High 7.5

Not known to be exploited · CVSS 7.5 High · fixed in Red Hat package updates : patch Red Hat soon.

Data as of 13 Nov 2026, 14:35 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 5.4.1, 4.3.2, 3.15.2

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Sep 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 13 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

Upgrade js-yaml to 5.4.1, 4.3.2 or 3.15.2.

Affected software

Product	Affected	Fixed in
nodecajs-yaml	Affected >=5.0.0 <5.4.1	Fixed in 5.4.1
nodecajs-yaml	Affected >=4.0.0 <4.3.2	Fixed in 4.3.2
nodecajs-yaml	Affected >=3.0.0 <3.15.2	Fixed in 3.15.2

AI-suggested

Red Hat has released updated OpenShift Virtualization v4.20 images that address this vulnerability. Users should apply these updated images and ensure all previously released relevant errata are installed. No additional mitigations are specified by Red Hat. There are no known exploits in the wild at this time.

Description

A denial of service (DoS) vulnerability exists in js-yaml, a JavaScript YAML parser used in Red Hat OpenShift Virtualization v4.20 images. The flaw allows an attacker to craft a specially designed YAML document that triggers excessive CPU consumption during merge key processing, potentially exhausting system resources and causing application unavailability. This vulnerability affects applications that process untrusted YAML input with merge processing enabled by default.

Impact

The vulnerability allows an attacker to cause a denial of service by exhausting CPU resources through crafted YAML input that triggers inefficient merge key processing in js-yaml. This can lead to prolonged application unavailability or degraded performance in environments processing untrusted YAML data with merge keys enabled.

Summary

CVE-2026-84375 is a denial of service vulnerability in the js-yaml JavaScript YAML parser component included in Red Hat OpenShift Virtualization v4.20 images. The vulnerability arises from inefficient handling of merge keys with empty sources, leading to prolonged CPU consumption when parsing maliciously crafted YAML documents. This can cause resource exhaustion and application unavailability. The issue is tracked under CWE-835 (Loop with Unreachable Exit Condition). Red Hat has published updated OpenShift Virtualization v4.20 images addressing this issue. The vulnerability is rated as medium severity by Red Hat with a CVSS v3 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H). No known exploits in the wild have been reported. Red Hat advises applying the updated images and ensuring all prior errata are applied.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Nov 2026, 14:35 UTC

WeaknessesCWE-835

Technical details

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