CVE-2026-88838

A flaw was found in BusyBox's udhcpc DHCP client. When processing raw DHCP packets, the client replaces the validated packet length with an attacker-controlled value from the IP header without re-validating the minimum size. This leads to an integer underflow when subtracting header sizes, causing a subsequent memory copy with a massively oversized length. An attacker on the same network segment can send a specially crafted packet to crash the DHCP client, resulting in denial of service and loss of network connectivity.

This CVE candidate has been rejected by Red Hat Product Security because it is not a security vulnerability. BusyBox internal TLS is intentionally minimal and documents in FEATURE_WGET_HTTPS that it does not verify peer identity or provide full TLS security; missing Finished verify_data checking is consistent with that documented design and does not cross a separate security boundary warranting a CVE.

In the add_match function in libbb/lineedit.c in BusyBox through 1.27.2, the tab autocomplete feature does not sanitize filenames, potentially leading to executing any escape sequences in the terminal.

Directory traversal vulnerability in the BusyBox implementation of tar before version 1.22.0 v5 allows remote attackers to point to files outside the current working directory via a symlink.

Integer overflow in the DHCP client (udhcpc) in BusyBox before version 1.25.0 allows remote attackers to cause a denial of service (crash) via a malformed RFC1035-encoded domain name, leading to an out-of-bounds heap write.

The recv_and_process_client_pkt function in networking/ntpd.c in busybox allows remote attackers to cause a denial of service via a forged NTP packet, triggering a communication loop.

The vulnerability in BusyBox affects the write_status_file() function in the dpkg tool. Failure to reset a stale field cursor between package stanzas leads to out-of-bounds reads and corruption of the status file when removing multiple packages.

A stack overflow vulnerability exists in ash.c:6030 in busybox before version 1.35. In the Internet of Vehicles environment, it can be exploited from command execution to arbitrary code execution.

A flaw was found in busybox. The tar applet's deferred link-creation handling for symlink and hardlink entries with unsafe-looking targets does not validate that the resolved destination remains inside the extraction directory once the deferred link is created. An attacker can craft a tar archive using a symlink target of exactly '..' combined with a deferred hardlink to create a new file outside the extraction directory, or reuse an extraction directory across two archives to replace an existing file outside it.

BusyBox TLS get_client_hello() reads past the end of the input buffer when parsing a truncated ClientHello message. This can result in an out-of-bounds read.