ZephyrProject Zephyr up to 4.4.1 6LoWPAN IPHC Uncompression subsys/net/ip/6lo.c get_ihpc_inlined_size out-of-bounds

Summaryinfo

A vulnerability has been found in ZephyrProject Zephyr up to 4.4.1 and classified as critical. This vulnerability affects the function get_ihpc_inlined_size of the file subsys/net/ip/6lo.c of the component 6LoWPAN IPHC Uncompression. Performing a manipulation results in out-of-bounds. This vulnerability is reported as CVE-2026-12630. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in ZephyrProject Zephyr up to 4.4.1. It has been classified as critical. This affects the function get_ihpc_inlined_size of the file subsys/net/ip/6lo.c of the component 6LoWPAN IPHC Uncompression. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. The summary by CVE is:

Zephyr's 6LoWPAN IP Header Compression (IPHC) uncompression code contains an out-of-bounds read in get_ihpc_inlined_size() (subsys/net/ip/6lo.c). The destination inline size is looked up in da_inline_size_table, which has 13 entries, using an index built from the M, DAC and DAM bits of the received IPHC dispatch word (iphc & NET_6LO_IPHC_DA_MASK, a 4-bit value of 0-15). The reserved combinations 13, 14 and 15 are not bounds-checked and read past the end of the table. The iphc word is taken directly from the received frame, and get_ihpc_inlined_size() is reached on every inbound 6LoWPAN frame via net_6lo_uncompress() from the 802.15.4 receive path (subsys/net/l2/ieee802154/ieee802154_6lo.c and ieee802154_6lo_fragment.c). An unauthenticated attacker on the radio/adjacent link can therefore craft a frame whose destination addressing-mode nibble selects an out-of-range index, with no privileges or user interaction. The out-of-bounds value becomes the computed inline_size, which then drives header reconstruction before the buffer-length check: it is used to dereference *(pkt->buffer->data + sizeof(iphc) + inline_size) and to compute a size_t diff that can underflow, leading to a further out-of-bounds read of the packet buffer and malformed uncompression. The practical impact is a radio-triggerable out-of-bounds read / denial-of-service on the receiver; the leaked byte is not returned to the attacker. The fix rejects any destination index beyond the table, aborting processing of the malformed frame.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-12630 since 06/18/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 4.4.2 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Project Management Software

Vendor

• ZephyrProject

Name

• Zephyr

Version

• 4.4.0
• 4.4.1

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion