CVE-2026-29004
BusyBox DHCPv6 Client Heap Buffer Overflow via DNS_SERVERS
- State
- Published
- Severity
- 7.2 High
- Published
- May 4, 2026
- Updated
- Jul 15, 2026
- Reserved
- Mar 3, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.2 High | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 8.1 High | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H | VulnCheck |
| 3.1 | 8.8 High | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
busybox_mirrorvda-linux |
|
References
- https://y637f9qq2x.com/posts/busybox-dhcpv6-heap-overflow/technical-descriptionexploit
- https://github.com/vda-linux/busybox_mirror/commit/42202bfb1e6ac51fa995beda8be4d7b654aeee2apatch
- https://github.com/vda-linux/busybox_mirror/commit/d368f3f7836d1c2484c8f839316e5c93e76d4409patch
- https://busybox.net/product
- https://www.vulncheck.com/advisories/busybox-dhcpv6-client-heap-buffer-overflow-via-dns-serversthird-party-advisory
- https://access.redhat.com/security/cve/CVE-2026-29004vdb-entry
- RHBZ#2466526issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29004.json
- https://access.redhat.com/errata/RHSA-2026:30652vendor-advisory
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