Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-71093 is a critical-severity Out-of-bounds Read (CWE-125) vulnerability in Linux Linux Kernel. Its CVSS base score is 9.1 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-71093 is an out-of-bounds read vulnerability in the Linux kernel's e1000 network driver, specifically within the e1000_tbi_should_accept() function. The issue arises during receive packet processing in the NAPI path (e1000_clean_rx_irq), where the function unconditionally reads the last byte of a frame via data[length - 1] without first validating the descriptor-reported length. If the length is zero or exceeds the actual RX buffer size (adapter->rx_buffer_len), this access extends beyond the allocated buffer, potentially reading unrelated slab objects. The vulnerability was detected by KASAN in kernel version 5.18.0-rc1, manifesting as a slab-out-of-bounds read during interrupt context.
A local attacker with low privileges (AV:L/AC:L/PR:L) can exploit this vulnerability with no user interaction required. By triggering conditions that produce invalid descriptor lengths in the RX path—observed concurrently with tasks like sshd transmitting data—the attacker can achieve high-impact confidentiality loss through reads of adjacent slab memory and high-impact availability disruption via kernel crashes or panics, as evidenced by the KASAN BUG report. The CVSS v3.1 base score is 7.1 (C:H/I:N/A:H), classified under CWE-125 (Out-of-bounds Read). No integrity impact is possible.
Mitigation requires applying upstream kernel patches from the referenced stable commits, which reject frames early if the length is zero or exceeds rx_buffer_len, preserving TBI workaround semantics for valid frames while preventing out-of-bounds access. Key patches include commits 26c8bebc2f25, 278b7cfe0d4d, 2c4c0c09f964, 4ccfa56f2722, and 9c72a5182ed9, available at git.kernel.org/stable. Security practitioners should update affected Linux kernels, particularly those using the e1000 driver for Intel PRO/1000 emulation (e.g., in QEMU environments).
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-2245
Vulnerability Data
In the Linux kernel, the following vulnerability has been resolved: e1000: fix OOB in e1000_tbi_should_accept() In e1000_tbi_should_accept() we read the last byte of the frame via 'data[length - 1]' to evaluate the TBI workaround. If the descriptor- reported length is…
more
zero or larger than the actual RX buffer size, this read goes out of bounds and can hit unrelated slab objects. The issue is observed from the NAPI receive path (e1000_clean_rx_irq): ================================================================== BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790 Read of size 1 at addr ffff888014114e54 by task sshd/363 CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x5a/0x74 print_address_description+0x7b/0x440 print_report+0x101/0x200 kasan_report+0xc1/0xf0 e1000_tbi_should_accept+0x610/0x790 e1000_clean_rx_irq+0xa8c/0x1110 e1000_clean+0xde2/0x3c10 __napi_poll+0x98/0x380 net_rx_action+0x491/0xa20 __do_softirq+0x2c9/0x61d do_softirq+0xd1/0x120 </IRQ> <TASK> __local_bh_enable_ip+0xfe/0x130 ip_finish_output2+0x7d5/0xb00 __ip_queue_xmit+0xe24/0x1ab0 __tcp_transmit_skb+0x1bcb/0x3340 tcp_write_xmit+0x175d/0x6bd0 __tcp_push_pending_frames+0x7b/0x280 tcp_sendmsg_locked+0x2e4f/0x32d0 tcp_sendmsg+0x24/0x40 sock_write_iter+0x322/0x430 vfs_write+0x56c/0xa60 ksys_write+0xd1/0x190 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f511b476b10 Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24 RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10 RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003 RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00 R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003 </TASK> Allocated by task 1: __kasan_krealloc+0x131/0x1c0 krealloc+0x90/0xc0 add_sysfs_param+0xcb/0x8a0 kernel_add_sysfs_param+0x81/0xd4 param_sysfs_builtin+0x138/0x1a6 param_sysfs_init+0x57/0x5b do_one_initcall+0x104/0x250 do_initcall_level+0x102/0x132 do_initcalls+0x46/0x74 kernel_init_freeable+0x28f/0x393 kernel_init+0x14/0x1a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff888014114000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1620 bytes to the right of 2048-byte region [ffff888014114000, ffff888014114800] The buggy address belongs to the physical page: page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110 head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x100000000010200(slab|head|node=0|zone=1) raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected ================================================================== This happens because the TBI check unconditionally dereferences the last byte without validating the reported length first: u8 last_byte = *(data + length - 1); Fix by rejecting the frame early if the length is zero, or if it exceeds adapter->rx_buffer_len. This preserves the TBI workaround semantics for valid frames and prevents touching memory beyond the RX buffer.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
Routine patching replaces vulnerable code containing out-of-bounds read flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.