Red Hat Enterprise Linux Hardened Images udhcpc6 use after free

Summaryinfo

A vulnerability classified as critical has been found in Red Hat Enterprise Linux Hardened Images. The affected element is an unknown function of the component udhcpc6. The manipulation leads to use after free. This vulnerability is traded as CVE-2026-124740. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Red Hat Enterprise Linux Hardened Images (version now known) and classified as critical. This issue affects some unknown processing of the component udhcpc6. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer. Impacted is availability. The summary by CVE is:

A flaw was found in BusyBox's udhcpc6 DHCPv6 client. A malicious server on the local network can trigger a use-after-free condition by responding with a crafted Dynamic Host Configuration Protocol for IPv6 (DHCPv6) reply packet lacking usable address options. This issue causes the client to read stale heap memory, which can result in a Denial of Service (DoS) due to an application crash or disclose previously assigned network address data in subsequent discovery requests.

The advisory is shared at access.redhat.com. The identification of this vulnerability is CVE-2026-124740 since 11/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 11/11/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Red Hat

Name

• Enterprise Linux Hardened Images

License

• open-source

Website

• Vendor: https://www.redhat.com/

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion