Answer in brief
CVE-2026-63831 records a High severity (CVSS 8.8) vulnerability in mac802154: llsec: add skb_cow_data() before in-place crypto. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <3a2b378b3a9ca75d3518d879148d2ad25b5714a9 || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <7a831bcd0486788283ef35e396d4282ee01bb0d5 || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <ff976ef7c39199ebff33c18034636595016db9f0 || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <e28e7fd34c449028325322a3f5127b92594b7396 || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <993fd674fe85d114e6a8d3963033d4fbbc2170a8 || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <bd968bdd568beacfdf98ec537a87527e85f1d0cf || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <86d531337ea1ba02d9f2bc830d07c683d9bfaade || >=03556e4d0dbbbf4af9df76f4a3839c86f6afb015 <84a04eb5b210643bd67aab81ff805d32f62aa865 | 3a2b378b3a9ca75d3518d879148d2ad25b5714a9, 7a831bcd0486788283ef35e396d4282ee01bb0d5, ff976ef7c39199ebff33c18034636595016db9f0, e28e7fd34c449028325322a3f5127b92594b7396, 993fd674fe85d114e6a8d3963033d4fbbc2170a8, bd968bdd568beacfdf98ec537a87527e85f1d0cf, 86d531337ea1ba02d9f2bc830d07c683d9bfaade, 84a04eb5b210643bd67aab81ff805d32f62aa865 |
| Linux/Linuxgeneric | 3.16 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: mac802154: llsec: add skb_cow_data() before in-place crypto llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data. They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the crypto API (e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt). On the RX path, __ieee802154_rx_handle_packet() clones the received skb before handing it to each subscriber via ieee802154_subif_frame(). The cloned skb shares the same underlying data buffer via reference counting. When llsec_do_decrypt() subsequently modifies this shared buffer in place, it corrupts data that other clones -- potentially belonging to other sockets or subsystems -- still reference. On the TX path, similar data sharing can occur when an skb's head has been cloned (skb_cloned() returns true). The fix is to call skb_cow_data() before performing any in-place crypto operation. skb_cow_data() ensures that the skb's data area is not shared: if the skb head is cloned or the data spans multiple fragments, it copies the data into a private buffer that can be safely modified in place. This is the same pattern used by: - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c) - MACsec (drivers/net/macsec.c) - WireGuard (drivers/net/wireguard/receive.c) - TIPC (net/tipc/crypto.c) Without this guard, in-place crypto on shared skb data leads to: - Silent data corruption of other skb clones - Use-after-free when the crypto API scatterwalk writes through a page that has already been freed by another clone's kfree_skb() - Kernel crashes under concurrent 802.15.4 traffic with security enabled (KASAN/KMSAN reports slab-use-after-free) Found by 0sec (https://0sec.ai) using automated source analysis.
Quoted source text, attributed separately from HOL analysis.