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CVE-2026-63991— Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于send_mcast_pkt()函数中未检查skb_clone()返回值，可能导致send_pkt()函数解引用NULL指针时发生空指针取消引用。

AI Predicted 7.8 Difficulty: Moderate EPSS 0.12% · P2

Possible ATT&CK Techniques 1 AI

T1211 · Exploitation for Stealth

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 18722c247023035b9e2e2a08a887adec2a9a6e49< 9afcb5ea080af13aab37930da627db43bd277665 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< 9903a04becf059e44cccf625e23689b7d4378384 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< d630c4b25f36e0e68461561e4c70957ec37fdedd affected
18722c247023035b9e2e2a08a887adec2a9a6e49< b06203ac5f12929d79146bb9f063c2af1d679e63 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< 3d5d81d294ba09487c86bc4ba33dc4a4bec5d215 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< e673889a35a5e4c586d0fae67d8755ca4367d3e2 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< 2061d080a013c0ec0a56162cd501fb36d2befc26 affected
18722c247023035b9e2e2a08a887adec2a9a6e49< 3c40d381ce04f9575a5d8b542898183c3b4b38dc affected
… +10 more rows
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I. Basic Information for CVE-2026-63991

Vulnerability Information
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Vulnerability Title
Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: 6lowpan: check skb_clone() return value in send_mcast_pkt() The skb_clone() function can return NULL if memory allocation fails. send_mcast_pkt() calls skb_clone() without checking the return value, which can lead to a NULL pointer dereference in send_pkt() when it dereferences skb->data. Add a NULL check after skb_clone() and skip the peer if the clone fails.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于send_mcast_pkt()函数中未检查skb_clone()返回值，可能导致send_pkt()函数解引用NULL指针时发生空指针取消引用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 18722c247023035b9e2e2a08a887adec2a9a6e49 ~ 9afcb5ea080af13aab37930da627db43bd277665 -
Linux Linux 3.14 -

II. Public POCs for CVE-2026-63991

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III. Intelligence Information for CVE-2026-63991

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Patches & Fixes for CVE-2026-63991 (6)

Same Patch Batch · Linux · 2026-07-19 · 429 CVEs total

CVE-2026-63795 10.0 CRITICAL 9p: avoid putting oldfid in p9_client_walk() error path
CVE-2026-63808 9.8 CRITICAL exfat: fix potential use-after-free in exfat_find_dir_entry()
CVE-2026-53399 9.8 CRITICAL nfsd: release layout stid on setlease failure
CVE-2026-53398 9.8 CRITICAL NFSD: Fix SECINFO_NO_NAME decode error cleanup
CVE-2026-63993 9.8 CRITICAL vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
CVE-2026-64089 9.8 CRITICAL batman-adv: tt: fix negative last_changeset_len
CVE-2026-64025 9.8 CRITICAL bpf, skmsg: fix verdict sk_data_ready racing with ktls rx
CVE-2026-64091 9.8 CRITICAL batman-adv: tt: fix TOCTOU race for reported vlans
CVE-2026-63984 9.8 CRITICAL ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()
CVE-2026-63800 9.8 CRITICAL pNFS: Fix use-after-free in pnfs_update_layout()
CVE-2026-64113 9.8 CRITICAL ixgbevf: fix use-after-free in VEPA multicast source pruning
CVE-2026-64037 9.8 CRITICAL wifi: iwlwifi: mld: fix TSO segmentation explosion when AMSDU is disabled
CVE-2026-63888 9.8 CRITICAL scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
CVE-2026-64136 9.8 CRITICAL smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
CVE-2026-63887 9.8 CRITICAL scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf
CVE-2026-63979 9.8 CRITICAL net/handshake: hand off the pinned file reference to accept_doit
CVE-2026-64061 9.8 CRITICAL netfs: Fix early put of sink folio in netfs_read_gaps()
CVE-2026-64102 9.8 CRITICAL RDMA/siw: Reject MPA FPDU length underflow before signed receive math
CVE-2026-64056 9.8 CRITICAL net: ethernet: cortina: Make RX SKB per-port
CVE-2026-64125 9.8 CRITICAL net: bcmgenet: keep RBUF EEE/PM disabled

Showing top 20 of 429 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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