{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-80847", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.797Z", "datePublished": "2026-09-04T15:54:57.441Z", "dateUpdated": "2026-09-04T15:54:57.441Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-04T15:54:57.441Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: clamp route advmss to TCP_MIN_MSS\n\ntcp_select_initial_window() assumes that callers never pass an MSS\nsmaller than 1, but route-derived advmss values can violate that\nassumption.\n\nA too-small explicit RTAX_ADVMSS is one way to get there, but it is not\nthe only one. The same divide-by-zero can also be reached through the\n\"default advmss\" path when RTAX_ADVMSS is left at 0 and the effective\nadvmss is later driven down by route MTU and min_adv_mss.\n\nIntroduce a tcp_dst_advmss() helper that clamps route advmss to\nTCP_MIN_MSS before TCP consumes it, and use it in the TCP paths that\nderive advmss from dst metrics. This keeps the effective MSS from\ndropping to zero before tcp_select_initial_window() rounds the receive\nwindow."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_minisocks.c", "net/ipv4/tcp_output.c", "net/ipv6/tcp_ipv6.c"], "versions": [{"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "6b8c20bf61924dfc38fefb145c9f7406d73fae53", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "31cf2349361902769dc323e4dbf4b449795ec288", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "870a9e42ecc6fe1b8c25d87af043cb0d9c178fe1", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_minisocks.c", "net/ipv4/tcp_output.c", "net/ipv6/tcp_ipv6.c"], "versions": [{"version": "2.6.12", "status": "affected"}, {"version": "0", "lessThan": "2.6.12", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.13", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.3", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3-rc1", "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": "2.6.12", "versionEndExcluding": "7.1.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.2.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.12", "versionEndExcluding": "7.3-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6b8c20bf61924dfc38fefb145c9f7406d73fae53"}, {"url": "https://git.kernel.org/stable/c/31cf2349361902769dc323e4dbf4b449795ec288"}, {"url": "https://git.kernel.org/stable/c/870a9e42ecc6fe1b8c25d87af043cb0d9c178fe1"}], "title": "tcp: clamp route advmss to TCP_MIN_MSS", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_minisocks.c", "net/ipv4/tcp_output.c", "net/ipv6/tcp_ipv6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "6b8c20bf61924dfc38fefb145c9f7406d73fae53", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "31cf2349361902769dc323e4dbf4b449795ec288", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}, {"lessThan": "870a9e42ecc6fe1b8c25d87af043cb0d9c178fe1", "status": "affected", "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_ipv4.c", "net/ipv4/tcp_minisocks.c", "net/ipv4/tcp_output.c", "net/ipv6/tcp_ipv6.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.12"}, {"lessThan": "2.6.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.13", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.3", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: clamp route advmss to TCP_MIN_MSS\n\ntcp_select_initial_window() assumes that callers never pass an MSS\nsmaller than 1, but route-derived advmss values can violate that\nassumption.\n\nA too-small explicit RTAX_ADVMSS is one way to get there, but it is not\nthe only one. The same divide-by-zero can also be reached through the\n\"default advmss\" path when RTAX_ADVMSS is left at 0 and the effective\nadvmss is later driven down by route MTU and min_adv_mss.\n\nIntroduce a tcp_dst_advmss() helper that clamps route advmss to\nTCP_MIN_MSS before TCP consumes it, and use it in the TCP paths that\nderive advmss from dst metrics. This keeps the effective MSS from\ndropping to zero before tcp_select_initial_window() rounds the receive\nwindow."}], "id": "CVE-2026-80847", "lastModified": "2026-09-04T16:18:13.430", "metrics": {}, "published": "2026-09-04T16:18:13.430", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/31cf2349361902769dc323e4dbf4b449795ec288"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6b8c20bf61924dfc38fefb145c9f7406d73fae53"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/870a9e42ecc6fe1b8c25d87af043cb0d9c178fe1"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}