{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53003","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.377Z","datePublished":"2026-06-24T16:29:15.268Z","dateUpdated":"2026-06-28T06:37:53.970Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-28T06:37:53.970Z"},"descriptions":[{"lang":"en","value":"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."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c","drivers/net/ppp/pppoe.c","include/linux/ppp_defs.h"],"versions":[{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"cb3beef35ab5e0c1afca9fd7648c6ae499786377","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"ba758fdf1399f310b30098b6faa3fd043de47dd2","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"fcca1df05322bb04e344dd1178b54b76a08eb7c3","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"8a5e840babc5c0fbd10c73728a13192347771ec6","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"0cab5d077dd1efd2bd1a47271acc35894f945b4f","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"2b5c3c040d020e3ab3b9a8887031202d96843b1e","status":"affected","versionType":"git"},{"version":"7fb1b8ca8fa1ee34ffc328f17f78da68c7cc04e6","lessThan":"cc1ff87bce1ccd38410ab10960f576dcd17db679","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ppp/ppp_generic.c","drivers/net/ppp/pppoe.c","include/linux/ppp_defs.h"],"versions":[{"version":"5.0","status":"affected"},{"version":"0","lessThan":"5.0","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.0","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/cb3beef35ab5e0c1afca9fd7648c6ae499786377"},{"url":"https://git.kernel.org/stable/c/ba758fdf1399f310b30098b6faa3fd043de47dd2"},{"url":"https://git.kernel.org/stable/c/fcca1df05322bb04e344dd1178b54b76a08eb7c3"},{"url":"https://git.kernel.org/stable/c/8a5e840babc5c0fbd10c73728a13192347771ec6"},{"url":"https://git.kernel.org/stable/c/49e41b60ccd1bdbe9e218420f716dd5f9a2f9c71"},{"url":"https://git.kernel.org/stable/c/0cab5d077dd1efd2bd1a47271acc35894f945b4f"},{"url":"https://git.kernel.org/stable/c/2b5c3c040d020e3ab3b9a8887031202d96843b1e"},{"url":"https://git.kernel.org/stable/c/cc1ff87bce1ccd38410ab10960f576dcd17db679"}],"title":"pppoe: drop PFC frames","x_generator":{"engine":"bippy-1.2.0"}}}}