CVE-2026-46306flow_dissector: do not dissect PPPoE PFC frames
- 7.5HighCVSS base score
- 0.45%Exploitation in 30 daysEPSS · top 60% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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/[email protected]
Timeline
ID reserved
By Linux
- 26 days later
· 26 days later
Published
- 5 months later
· 5 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.45% · top 60% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected 10f665b52a75df6eb26ddebbbc072ee264183731 – < e7c811ca372d53c2be7d01a1614e71fae1054836
- affected d7e541e86122d21f71eb71c5dfa7fb1eb6623fe8 – < abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < 18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < db104b0d8a7856397c0469d83a4289adf7c54863
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < 6044392d9cace3a3672b02c8bc7d38b502e51734
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < 0d00b9015069712944934bab09eaa6c542143049
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < 7c93f353eab4ea911e394630f07d72e040a729d8
- affected 46126db9c86110e5fc1e369b9bb89735ddefdae4 – < d6c19b31a3c1d519fabdcf0aa239e6b6109b9473
- affected 6.0
- unaffected < 6.0
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.140 – ≤ 6.6.*
- unaffected 6.12.88 – ≤ 6.12.*
- unaffected 6.18.30 – ≤ 6.18.*
- unaffected 7.0.7 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References11
- https://git.kernel.org/stable/c/e7c811ca372d53c2be7d01a1614e71fae1054836 (opens in a new tab)
- https://git.kernel.org/stable/c/abc5bc84e0f2edc7ea2d437afa6ef3fe1fc43200 (opens in a new tab)
- https://git.kernel.org/stable/c/18ae9eacfc95cc715c0606b2c86e8aa8a86cf3e3 (opens in a new tab)
- https://git.kernel.org/stable/c/db104b0d8a7856397c0469d83a4289adf7c54863 (opens in a new tab)
- https://git.kernel.org/stable/c/6044392d9cace3a3672b02c8bc7d38b502e51734 (opens in a new tab)
- https://git.kernel.org/stable/c/0d00b9015069712944934bab09eaa6c542143049 (opens in a new tab)
- https://git.kernel.org/stable/c/7c93f353eab4ea911e394630f07d72e040a729d8 (opens in a new tab)
- https://git.kernel.org/stable/c/d6c19b31a3c1d519fabdcf0aa239e6b6109b9473 (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html (opens in a new tab)
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-35171 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-46306)Record last updated .