VulnerabilityPublished 11 Nov 2026

CVE-2026-124740: Red Hat Hardened Images · Use After Free

Affects Red Hat Hardened ImagesSource CVE Database V5

Compare

Not known to be exploited · CVSS 4.3 Medium.

Data as of 11 Nov 2026, 11:49 UTC

CVSS 3.1 base score

4.3Medium

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (redhat)	CVSS 3.1	4.3

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

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

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

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Nov 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 11 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

Affected software

Product	Affected	Fixed in
Red Hat Enterprise Linux 6busybox	Affected–	Fixed in–
Red Hat Hardened Imagesbusybox	Affected–	Fixed in–

AI-suggested

Red Hat currently does not offer a mitigation or patch that meets their criteria for ease of deployment, applicability, or stability. Users should avoid deploying BusyBox udhcpc6 DHCPv6 client in environments exposed to untrusted local networks or rogue DHCPv6 servers. Standard Red Hat Enterprise Linux installations using NetworkManager are not affected. Monitor Red Hat advisories for any future updates or fixes.

Description

A use-after-free vulnerability exists in BusyBox's udhcpc6 DHCPv6 client used in Red Hat Hardened Images. A malicious local network DHCPv6 server can trigger this flaw by sending a crafted reply packet without usable address options, causing the client to read stale heap memory. This can lead to a denial of service due to application crash or disclosure of previously assigned network address data. The vulnerability is rated medium severity with a CVSS score of 4.3. It affects environments where BusyBox udhcpc6 is explicitly used, such as custom containers or minimal recovery images, but not standard Red Hat Enterprise Linux installations which use NetworkManager by default. No official fix or mitigation is currently available that meets Red Hat's criteria for deployment and stability.

Impact

Exploitation requires an adjacent attacker controlling a rogue DHCPv6 server on the local network. The impact is limited to denial of service due to application crash or disclosure of stale heap memory containing previously assigned network address data. There is no impact on confidentiality or integrity beyond this data disclosure. Standard Red Hat Enterprise Linux installations are not affected as they do not use BusyBox udhcpc6 by default. The vulnerability is thus limited to custom environments, containers, or minimal recovery images where BusyBox udhcpc6 is explicitly used.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2026, 11:34 UTC

Technical details

References

Community reviews

Related threats