{"id":"CVE-2026-53003","revision":"de7daf9e71e5416897cea63cdca1728b","records":[{"revision":"de7daf9e71e5416897cea63cdca1728b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-53003","aliases":[],"title":"pppoe: drop PFC frames","description":"In the Linux kernel, the following vulnerability has been resolved:\n\npppoe: drop PFC frames\n\nRFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT\nRECOMMENDED for PPPoE. In practice, pppd does not support negotiating\nPFC for PPPoE sessions, and the current PPPoE driver assumes an\nuncompressed (2-byte) protocol field. However, the generic PPP layer\nfunction ppp_input() is not aware of the negotiation result, and still\naccepts PFC frames.\n\nIf a peer with a broken implementation or an attacker sends a frame with\na compressed (1-byte) protocol field, the subsequent PPP payload is\nshifted by one byte. This causes the network header to be 4-byte\nmisaligned, which may trigger unaligned access exceptions on some\narchitectures.\n\nTo reduce the attack surface, drop PPPoE PFC frames. Introduce\nppp_skb_is_compressed_proto() helper function to be used in both\nppp_generic.c and pppoe.c to avoid open-coding.","state":0,"publishedAt":"2026-06-24T16:29:15.268+00:00","modifiedAt":"2026-10-19T19:47:13.28+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/net/ppp/ppp_generic.c\",\n                        \"drivers/net/ppp/pppoe.c\",\n                        \"include/linux/ppp_defs.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"cb3beef35ab5e0c1afca9fd7648c6ae499786377\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"ba758fdf1399f310b30098b6faa3fd043de47dd2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"fcca1df05322bb04e344dd1178b54b76a08eb7c3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"8a5e840babc5c0fbd10c73728a13192347771ec6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"0cab5d077dd1efd2bd1a47271acc35894f945b4f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"2b5c3c040d020e3ab3b9a8887031202d96843b1e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6\",\n                            \"lessThan\": \"cc1ff87bce1ccd38410ab10960f576dcd17db679\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/net/ppp/ppp_generic.c\",\n                        \"drivers/net/ppp/pppoe.c\",\n                        \"include/linux/ppp_defs.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.258\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.209\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.141\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.91\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.33\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.10\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/cb3beef35ab5e0c1afca9fd7648c6ae499786377","https://git.kernel.org/stable/c/ba758fdf1399f310b30098b6faa3fd043de47dd2","https://git.kernel.org/stable/c/fcca1df05322bb04e344dd1178b54b76a08eb7c3","https://git.kernel.org/stable/c/8a5e840babc5c0fbd10c73728a13192347771ec6","https://git.kernel.org/stable/c/49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71","https://git.kernel.org/stable/c/0cab5d077dd1efd2bd1a47271acc35894f945b4f","https://git.kernel.org/stable/c/2b5c3c040d020e3ab3b9a8887031202d96843b1e","https://git.kernel.org/stable/c/cc1ff87bce1ccd38410ab10960f576dcd17db679"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-53003","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-53003","identifiers":["CVE-2026-53003"]},"retained":false,"historicalAffected":[]}],"coverage":[]}