CVSS 3.1
7.6 highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:HCVE-2026-124741 Busybox: stack buffer overflow in udhcpc6 send_d6_renew() and send_d6_release()
High (7.6) in red hat. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.
On this page
A flaw was found in BusyBox. The udhcpc6 DHCPv6 client does not properly validate the size of network options sent by a server before copying them into memory. A malicious DHCPv6 server on the local network can exploit this flaw by sending a crafted reply, triggering a stack-based buffer overflow. This vulnerability could allow an attacker to achieve arbitrary code execution with root privileges or cause a denial of service (DoS) crash.
Severity
- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 20th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-787 Out-of-bounds Write
- Published
- Modified
- Assigned by
- redhat (CNA)
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Affected
- red hat:red hat enterprise linux 6
- red hat:red hat hardened images
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Ubuntu | 20.04:LTS, 22.04:LTS, 24.04:LTS and 5 more | busybox | no fix listed | UBUNTU-CVE-2026-124741 |
From the distributions' data via OSV.dev: Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Ubuntu.
Red Hat
Red Hat rates this Important.
This vulnerability is rated as having an Important impact for Red Hat products because, while exploitation is constrained to adjacent network attackers on the local link, the client process typically runs with superuser privileges, allowing a rogue DHCPv6 server to potentially achieve arbitrary code execution or cause a denial of service. In standard Red Hat Enterprise Linux installations, BusyBox is not used as the default network management or DHCP client, as networking is handled by NetworkManager. Consequently, exposure is limited to specialized or embedded environments where BusyBox's udhcpc6 utility is explicitly invoked for IPv6 network configuration.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 6 | busybox | Not affected | |
| Red Hat Hardened Images | busybox | Affected |
Contains Red Hat Security Data © Red Hat, Inc., licensed under CC BY 4.0. Source: https://access.redhat.com/security/data. Modified: reformatted. Red Hat's page for CVE-2026-124741.