Answer in brief
CVE-2026-63831 records a Unknown severity 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.
Answer in brief
CVE-2026-63831 records a Unknown severity 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.
A CVSS score is not reported in the current record. 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.
| 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
Aug 5, 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.
A CVSS score is not reported in the current record. 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.
| 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
Aug 5, 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.