CVE-2023-53726High· 7.1▾ Twilight

In the Linux kernel, the following vulnerability has been resolved: arm64: csum: Fix OoB access in IP checksum code for negative lengths Although commit c2c24edb1d9c ("arm64: csum: Fix pathological zero-length calls") added an early re…

▾ Twilight zone — High severity, or a signal on a lesser flaw

Depth score39/ 100 · Low

impact 39.1 · likelihood 0 · exploitation 0

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Proof of concept

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Published

Oct 22, 2025

Updated

Oct 15, 2026

CVSS

7.1

Vendor

Linux

Product

Linux

CWE

—

Depth score

39 · Low

EPSS

0.15% · p4

Platforms

—

Source

NVD

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

CISA SSVC

decided 2026-10-15

Exploitation: none
Automatable: no
Technical impact: partial

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.

EPSS history

Exploit-prediction probability, daily snapshots since Oct 15.

0.1% → 0.1%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 358 days

Oct 22, 2025Published
Disclosed via NVD
Oct 15, 2026Record revised
Last analysed / modified upstream
Oct 15, 2026EPSS first tracked
0.1%

Linux #nvd #cve.org

Affected

Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < 5a85727239a23de1cc8d93985f1056308128f3e2
Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < 9a43563cfd6b9200ff2f76b3f9fcdcb217ceb523
Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < ba0b46166b8e547024d02345a68b747841931ad2
Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < a5ad2f87d8e74e351d3f500ad9d5b3a5653e1c6f
Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < fcdf904e866de0e3715835e50409fda3b2590527
Linux >= 5777eaed566a1d63e344d3dd8f2b5e33be20643e < 8bd795fedb8450ecbef18eeadbd23ed8fc7630f5
Linux 5.6

Full technical detail▾

Overview

In the Linux kernel, the following vulnerability has been resolved:

arm64: csum: Fix OoB access in IP checksum code for negative lengths

Although commit c2c24edb1d9c ("arm64: csum: Fix pathological zero-length calls") added an early return for zero-length input, syzkaller has popped up with an example of a negative length which causes an undefined shift and an out-of-bounds read:

| BUG: KASAN: slab-out-of-bounds in do_csum+0x44/0x254 arch/arm64/lib/csum.c:39 | Read of size 4294966928 at addr ffff0000d7ac0170 by task syz-executor412/5975 | | CPU: 0 PID: 5975 Comm: syz-executor412 Not tainted 6.4.0-rc4-syzkaller-g908f31f2a05b #0 | Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 | Call trace: | dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 | show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 | __dump_stack lib/dump_stack.c:88 [inline] | dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 | print_address_description mm/kasan/report.c:351 [inline] | print_report+0x174/0x514 mm/kasan/report.c:462 | kasan_report+0xd4/0x130 mm/kasan/report.c:572 | kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187 | __kasan_check_read+0x20/0x30 mm/kasan/shadow.c:31 | do_csum+0x44/0x254 arch/arm64/lib/csum.c:39 | csum_partial+0x30/0x58 lib/checksum.c:128 | gso_make_checksum include/linux/skbuff.h:4928 [inline] | __udp_gso_segment+0xaf4/0x1bc4 net/ipv4/udp_offload.c:332 | udp6_ufo_fragment+0x540/0xca0 net/ipv6/udp_offload.c:47 | ipv6_gso_segment+0x5cc/0x1760 net/ipv6/ip6_offload.c:119 | skb_mac_gso_segment+0x2b4/0x5b0 net/core/gro.c:141 | __skb_gso_segment+0x250/0x3d0 net/core/dev.c:3401 | skb_gso_segment include/linux/netdevice.h:4859 [inline] | validate_xmit_skb+0x364/0xdbc net/core/dev.c:3659 | validate_xmit_skb_list+0x94/0x130 net/core/dev.c:3709 | sch_direct_xmit+0xe8/0x548 net/sched/sch_generic.c:327 | __dev_xmit_skb net/core/dev.c:3805 [inline] | __dev_queue_xmit+0x147c/0x3318 net/core/dev.c:4210 | dev_queue_xmit include/linux/netdevice.h:3085 [inline] | packet_xmit+0x6c/0x318 net/packet/af_packet.c:276 | packet_snd net/packet/af_packet.c:3081 [inline] | packet_sendmsg+0x376c/0x4c98 net/packet/af_packet.c:3113 | sock_sendmsg_nosec net/socket.c:724 [inline] | sock_sendmsg net/socket.c:747 [inline] | __sys_sendto+0x3b4/0x538 net/socket.c:2144

Extend the early return to reject negative lengths as well, aligning our implementation with the generic code in lib/checksum.c

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd#cve.org