# CVE-2026-124741: Busybox: stack buffer overflow in udhcpc6 send_d6_renew() and send_d6_release()

Status: published. Published: 2026-11-11. Updated: 2026-11-11.

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.

## Remediation

- workaround: 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. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 6 (busybox): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Hardened Images (busybox): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 7.6 (high); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H; source: CNA: redhat

- CVSS 3.1: 7.6 (high); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-124741 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2571617 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-124741 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2571617 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-124741; retrieved 2026-11-11; source updated 2026-11-11

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-124741; retrieved 2026-11-11; source updated 2026-11-11

Revision: b5e2085ccb89080e264dfd82ae2ba9b8e5b73fdbe7e3242343d045a2298a51ba

Canonical: https://y2.dev/cve/CVE-2026-124741

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