CVE-2026-29004

Summary

BusyBox before commit 42202bf contains a heap buffer overflow vulnerability in the DHCPv6 client (udhcpc6) DNS_SERVERS option handler in networking/udhcp/d6_dhcpc.c that allows network-adjacent attackers to trigger memory corruption by sending a crafted DHCPv6 response with a malformed D6_OPT_DNS_SERVERS option. Attackers can exploit incorrect heap buffer allocation calculations in the option_to_env() function to cause denial of service or achieve arbitrary code execution on embedded systems without heap hardening.

Affected Software

Weaknesses

• CWE-122: CWE-122: Heap-based Buffer Overflow

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: partial

BusyBox: BusyBox: Arbitrary Code Execution via DHCPv6 Client Heap Buffer Overflow

Additional References

• https://access.redhat.com/security/cve/CVE-2026-29004
• https://bugzilla.redhat.com/show_bug.cgi?id=2466526
• https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29004.json
• https://access.redhat.com/errata/RHSA-2026:30652

References

• https://y637f9qq2x.com/posts/busybox-dhcpv6-heap-overflow/
• https://github.com/vda-linux/busybox_mirror/commit/42202bfb1e6ac51fa995beda8be4d7b654aeee2a
• https://github.com/vda-linux/busybox_mirror/commit/d368f3f7836d1c2484c8f839316e5c93e76d4409
• https://busybox.net/
• https://www.vulncheck.com/advisories/busybox-dhcpv6-client-heap-buffer-overflow-via-dns-servers

• ←Previous
• Next→