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CVE-2026-53250— xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()

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基金会开源的操作系统Linux所使用的内核。 Linux kernel存在安全漏洞,该漏洞源于xsk_skb_metadata()函数中csum_start和csum_offset存在TOCTOU竞争条件,可能导致恶意用户空间应用程序通过并发写入绕过边界检查,造成传输路径中校验和计算时越界内存访问。

CVSS 7.8 · High EPSS 0.10% · P1

Possible ATT&CK Techniques 1 AI

T1068 · Exploitation for Privilege Escalation

Affected Version Matrix 10

VendorProduct Version RangeStatus
Linux Linux 48eb03dd26304c24f03bdbb9382e89c8564e71df< eb778aed8a9b2381668fcb1247ae4fa011224768 affected
48eb03dd26304c24f03bdbb9382e89c8564e71df< 0dfe05b938435892875e07771170051346412df9 affected
48eb03dd26304c24f03bdbb9382e89c8564e71df< bfdfd2706d5fb2cd496a1506e680daf979309c8b affected
48eb03dd26304c24f03bdbb9382e89c8564e71df< 22ba97ea9cc1f63a0d0244fae38057ed452b6ac7 affected
6.8 affected
< 6.8 unaffected
6.12.110≤ 6.12.* unaffected
6.18.36≤ 6.18.* unaffected
… +2 more rows
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I. Basic Information for CVE-2026-53250

Vulnerability Information

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Vulnerability Title
xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: xsk: cache csum_start/csum_offset to fix TOCTOU in xsk_skb_metadata() The TX metadata area resides in the UMEM buffer which is memory-mapped and concurrently writable by userspace. In xsk_skb_metadata(), csum_start and csum_offset are read from shared memory for bounds validation, then read again for skb assignment. A malicious userspace application can race to overwrite these values between the two reads, bypassing the bounds check and causing out-of-bounds memory access during checksum computation in the transmit path. Fix this by reading csum_start and csum_offset into local variables once, then using the local copies for both validation and assignment. Note that other metadata fields (flags, launch_time) and the cached csum fields may be mutually inconsistent due to concurrent userspace writes, but this is benign: the only security-critical invariant is that each field's validated value is the same one used, which local caching guarantees.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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基金会开源的操作系统Linux所使用的内核。 Linux kernel存在安全漏洞,该漏洞源于xsk_skb_metadata()函数中csum_start和csum_offset存在TOCTOU竞争条件,可能导致恶意用户空间应用程序通过并发写入绕过边界检查,造成传输路径中校验和计算时越界内存访问。
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 48eb03dd26304c24f03bdbb9382e89c8564e71df ~ eb778aed8a9b2381668fcb1247ae4fa011224768 -
Linux Linux 6.8 -

II. Public POCs for CVE-2026-53250

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III. Intelligence Information for CVE-2026-53250

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Patches & Fixes for CVE-2026-53250 (4)

Same Patch Batch · Linux · 2026-06-25 · 146 CVEs total

CVE-2026-53175 9.8 CRITICAL inet: frags: fix use-after-free caused by the fqdir_pre_exit() flush
CVE-2026-53176 9.8 CRITICAL IB/isert: Reject login PDUs shorter than ISER_HEADERS_LEN
CVE-2026-53228 9.8 CRITICAL ipv6: sit: reload inner IPv6 header after GSO offloads
CVE-2026-53221 9.8 CRITICAL ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup()
CVE-2026-53246 9.8 CRITICAL sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing
CVE-2026-53247 9.8 CRITICAL net: ethernet: mtk_eth_soc: Fix use-after-free in metadata dst teardown
CVE-2026-53151 9.8 CRITICAL rxrpc: Fix the ACK parser to extract the SACK table for parsing
CVE-2026-53260 9.8 CRITICAL tcp: Add preempt_{disable,enable}_nested() in reqsk_queue_hash_req().
CVE-2026-53216 9.8 CRITICAL net: mvpp2: limit XDP frame size to the RX buffer
CVE-2026-53215 9.8 CRITICAL net: mvpp2: refill RX buffers before XDP or skb use
CVE-2026-53131 9.4 CRITICAL netfilter: require Ethernet MAC header before using eth_hdr()
CVE-2026-53225 9.1 CRITICAL sctp: fix uninit-value in __sctp_rcv_asconf_lookup()
CVE-2026-53224 9.1 CRITICAL sctp: validate embedded INIT chunk and address list lengths in cookie
CVE-2026-53186 9.1 CRITICAL RDMA/srp: bound SRP_RSP sense copy by the received length
CVE-2026-53159 8.8 HIGH misc: fastrpc: fix DMA address corruption due to find_vma misuse
CVE-2026-53198 8.8 HIGH ksmbd: fix use-after-free of a deferred file_lock on double SMB2_CANCEL
CVE-2026-53240 8.8 HIGH xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload
CVE-2026-53275 8.8 HIGH ipv6: mcast: Fix use-after-free when processing MLD queries
CVE-2026-53188 8.8 HIGH RDMA/core: Validate the passed in fops for ib_get_ucaps()
CVE-2026-53171 8.8 HIGH accel/ethosu: fix arithmetic issues in dma_length()

Showing top 20 of 146 CVEs. View all on vendor page &rarr; →

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