CVE-2026-46306

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-46306
In the Linux kernel, the following vulnerability has been resolved: flow_dissector: do not dissect PPPoE PFC frames RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT RECOMMENDED for PPPoE. In practice, pppd does not support negotiating PFC for PPPoE sessions, and the flow dissector driver has assumed an uncompressed frame until the blamed commit. During the review process of that commit [1], support for PFC is suggested. However, having a compressed (1-byte) protocol field means the subsequent PPP payload is shifted by one byte, causing 4-byte misalignment for the network header and an unaligned access exception on some architectures. The exception can be reproduced by sending a PPPoE PFC frame to an ethernet interface of a MIPS board, with RPS enabled, even if no PPPoE session is active on that interface: $ 0 : 00000000 80c40000 00000000 85144817 $ 4 : 00000008 00000100 80a75758 81dc9bb8 $ 8 : 00000010 8087ae2c 0000003d 00000000 $12 : 000000e0 00000039 00000000 00000000 $16 : 85043240 80a75758 81dc9bb8 00006488 $20 : 0000002f 00000007 85144810 80a70000 $24 : 81d1bda0 00000000 $28 : 81dc8000 81dc9aa8 00000000 805ead08 Hi : 00009d51 Lo : 2163358a epc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50 ra : 805ead08 __skb_get_hash_net+0x74/0x12c Status: 11000403 KERNEL EXL IE Cause : 40800010 (ExcCode 04) BadVA : 85144817 PrId : 0001992f (MIPS 1004Kc) Call Trace: [<805e91f0>] __skb_flow_dissect+0x1b0/0x1b50 [<805ead08>] __skb_get_hash_net+0x74/0x12c [<805ef330>] get_rps_cpu+0x1b8/0x3fc [<805fca70>] netif_receive_skb_list_internal+0x324/0x364 [<805fd120>] napi_complete_done+0x68/0x2a4 [<8058de5c>] mtk_napi_rx+0x228/0xfec [<805fd398>] __napi_poll+0x3c/0x1c4 [<805fd754>] napi_threaded_poll_loop+0x234/0x29c [<805fd848>] napi_threaded_poll+0x8c/0xb0 [<80053544>] kthread+0x104/0x12c [<80002bd8>] ret_from_kernel_thread+0x14/0x1c Code: 02d51821 1060045b 00000000 <8c640000> 3084000f 2c820005 144001a2 00042080 8e220000 To reduce the attack surface and maintain performance, do not process PPPoE PFC frames. [1] https://lore.kernel.org/r/20220630231016.GA392@debian.home

7.5 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049 Patch
https://git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 Patch
https://git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734 Patch
https://git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8 Patch
https://git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 Patch
https://git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 Patch
https://git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863 Patch
https://git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

23 Jul 2026, 08:10

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: flow_dissector: no diseccionar tramas PPPoE PFC La Sección 7 del RFC 2516 establece que la Compresión de Campo de Protocolo (PFC) NO ES RECOMENDADA para PPPoE. En la práctica, pppd no soporta la negociación de PFC para sesiones PPPoE, y el controlador del disector de flujo ha asumido una trama sin comprimir hasta el commit en cuestión. Durante el proceso de revisión de ese commit [1], se sugiere el soporte para PFC. Sin embargo, tener un campo de protocolo comprimido (de 1 byte) significa que la carga útil PPP subsiguiente se desplaza un byte, causando una desalineación de 4 bytes para el encabezado de red y una excepción de acceso no alineado en algunas arquitecturas. La excepción puede reproducirse enviando una trama PPPoE PFC a una interfaz ethernet de una placa MIPS, con RPS habilitado, incluso si no hay ninguna sesión PPPoE activa en esa interfaz: $ 0 : 00000000 80c40000 00000000 85144817 $ 4 : 00000008 00000100 80a75758 81dc9bb8 $ 8 : 00000010 8087ae2c 0000003d 00000000 $12 : 000000e0 00000039 00000000 00000000 $16 : 85043240 80a75758 81dc9bb8 00006488 $20 : 0000002f 00000007 85144810 80a70000 $24 : 81d1bda0 00000000 $28 : 81dc8000 81dc9aa8 00000000 805ead08 Hi : 00009d51 Lo : 2163358a epc : 805e91f0 __skb_flow_dissect+0x1b0/0x1b50 ra : 805ead08 __skb_get_hash_net+0x74/0x12c Status: 11000403 KERNEL EXL IE Cause : 40800010 (ExcCode 04) BadVA : 85144817 PrId : 0001992f (MIPS 1004Kc) Traza de Llamada: [<805e91f0>] __skb_flow_dissect+0x1b0/0x1b50 [<805ead08>] __skb_get_hash_net+0x74/0x12c [<805ef330>] get_rps_cpu+0x1b8/0x3fc [<805fca70>] netif_receive_skb_list_internal+0x324/0x364 [<805fd120>] napi_complete_done+0x68/0x2a4 [<8058de5c>] mtk_napi_rx+0x228/0xfec [<805fd398>] __napi_poll+0x3c/0x1c4 [<805fd754>] napi_threaded_poll_loop+0x234/0x29c [<805fd848>] napi_threaded_poll+0x8c/0xb0 [<80053544>] kthread+0x104/0x12c [<80002bd8>] ret_from_kernel_thread+0x14/0x1c Código: 02d51821 1060045b 00000000 <8c640000> 3084000f 2c820005 144001a2 00042080 8e220000 Para reducir la superficie de ataque y mantener el rendimiento, no procesar las tramas PPPoE PFC. [1] https://lore.kernel.org/r/20220630231016.GA392@debian.home

08 Jul 2026, 14:47

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049 - () https://git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049 - Patch
References () https://git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 - () https://git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 - Patch
References () https://git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734 - () https://git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734 - Patch
References () https://git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8 - () https://git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8 - Patch
References () https://git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 - () https://git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 - Patch
References () https://git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 - () https://git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 - Patch
References () https://git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863 - () https://git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863 - Patch
References () https://git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836 - () https://git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836 - Patch
CWE NVD-CWE-noinfo
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
First Time Linux linux Kernel
Linux

14 Jun 2026, 06:16

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.5

08 Jun 2026, 17:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-06-08 17:16

Updated : 2026-07-23 08:10

NVD link : CVE-2026-46306

Mitre link : CVE-2026-46306

CVE.ORG link : CVE-2026-46306

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
NVD-CWE-noinfo