CVE-2026-12630
6LoWPAN IPHC uncompression out-of-bounds read on reserved destination addressing mode
Published Aug 17, 2026
CVSS 3.1 · 4.3 Medium
EPSS < 1%
KEV · Not listed
Description
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 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.
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| zephyrproject | zephyr | unaffected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||
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| Zephyrproject | Zephyr |
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Remediation
Tracking
Advisories
Metrics
No CVSS v4.0
Attack Vector Adjacent Network
Attack Complexity Low
Privileges Required None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact Low
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.260% probability within 30 days)
Exploitation none
Automatable no
Technical Impact partial
References
History
Aug 18, 2026 1:30 PM
Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Aug 17, 2026 5:45 PM
First appearance in the feed. Affected vendors updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Zephyrproject
Zephyrproject zephyr |
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| Vendors & Products |
Zephyrproject
Zephyrproject zephyr |
Aug 17, 2026 4:30 PM
Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | 6LoWPAN IPHC uncompression out-of-bounds read on reserved destination addressing mode | |
| Weaknesses | CWE-125 | |
| References |
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| Metrics |
cvssV3_1
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Subscriptions
Weaknesses
