{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-68118", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.369Z", "datePublished": "2026-08-10T11:58:38.000Z", "dateUpdated": "2026-08-13T22:39:53.475Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-13T22:39:53.475Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntcp: challenge ACK for non-exact RST in SYN-RECEIVED\n\nThe SYN-RECEIVED request-socket path in tcp_check_req() accepts an\nin-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A\nnon-exact RST therefore removes the request instead of eliciting a\nchallenge ACK.\n\nRFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in\nSYN-RECEIVED: an exact RST resets the connection, while a non-exact\nin-window RST must trigger a challenge ACK and be dropped.\n\nApply that check before the ACK-field validation, following the RFC\nsequence-number, RST, then ACK processing order. Factor the per-netns\nchallenge ACK quota out of tcp_send_challenge_ack() so request sockets\ncan share it. Use the request socket's send_ack() callback and its own\nout-of-window ACK timestamp to send and rate-limit the response."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 8.2, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The bug is in tcp_check_req() on the core TCP receive path (ip_rcv/tcp_v4_rcv or tcp_v6_rcv \u2192 __inet_lookup_skb on TCP_NEW_SYN_RECV \u2192 tcp_check_req); any remote host that can deliver TCP segments to an internet-facing listener reaches it with no local access.\nAC:L - An attacker controls the forged RST (source/dest ports, SEQ sweep across the SYN-RECEIVED window up to tcp_synack_window/65535) and can retry on every handshake; no race, rare config, or victim-only state outside attacker influence is required beyond routine IP spoofing or on-path delivery.\nPR:N - Processing occurs on the pre-authentication TCP handshake path for embryonic request sockets; no credentials, capabilities, or local account are needed\u2014only the ability to send (or spoof) TCP packets to the target listener.\nUI:N - Handshake teardown is triggered automatically when the kernel receives the crafted RST during SYN-RECEIVED; no victim must open files, click links, or perform any other action.\nS:U - Impact is confined to incorrect TCP connection-state handling within the same host kernel; it does not cross VM, container, or IOMMU security boundaries.\nC:N - This is a protocol state-machine logic flaw with no memory corruption, out-of-bounds access, use-after-free, or information disclosure\u2014only embryonic request-socket teardown occurs.\nI:L - A non-exact in-window RST causes unauthorized modification of TCP connection state by dropping the embryonic request socket (embryonic_reset/inet_csk_reqsk_queue_drop) instead of preserving it per RFC 5961/RFC 9293.\nA:H - Repeated spoofed in-window RSTs during SYN-RECEIVED can prevent TCP handshakes from completing on arbitrary listening services (HTTPS, SSH, databases, load balancers), causing sustained denial of service without kernel crash."}]}], "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_input.c", "net/ipv4/tcp_minisocks.c"], "versions": [{"version": "282f23c6ee343126156dd41218b22ece96d747e3", "lessThan": "234f9ffbd9b2c1b24ec67200ea3cff07401bec48", "status": "affected", "versionType": "git"}, {"version": "282f23c6ee343126156dd41218b22ece96d747e3", "lessThan": "22cec809b048495310f206d9abbcdbbfbdce3ae3", "status": "affected", "versionType": "git"}, {"version": "282f23c6ee343126156dd41218b22ece96d747e3", "lessThan": "a28c4fcbf774e23b4779cae468e3497a5ad1f4a1", "status": "affected", "versionType": "git"}, {"version": "86791bbfe5ed7b275be040cfeff049a1624af1b7", "status": "affected", "versionType": "git"}, {"version": "61f69dc4e40e41b0018f00fa4aeb23d3239556fb", "status": "affected", "versionType": "git"}, {"version": "34fb350281ced2a72707a5c0064f69992d440edb", "status": "affected", "versionType": "git"}, {"version": "3.0.58", "lessThan": "3.1", "status": "affected", "versionType": "semver"}, {"version": "3.2.37", "lessThan": "3.3", "status": "affected", "versionType": "semver"}, {"version": "3.4.25", "lessThan": "3.5", "status": "affected", "versionType": "semver"}]}, {"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_input.c", "net/ipv4/tcp_minisocks.c"], "versions": [{"version": "3.6", "status": "affected"}, {"version": "0", "lessThan": "3.6", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc5", "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": "3.6", "versionEndExcluding": "6.18.42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "7.1.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.6", "versionEndExcluding": "7.2-rc5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.0.58"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2.37"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.4.25"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/234f9ffbd9b2c1b24ec67200ea3cff07401bec48"}, {"url": "https://git.kernel.org/stable/c/22cec809b048495310f206d9abbcdbbfbdce3ae3"}, {"url": "https://git.kernel.org/stable/c/a28c4fcbf774e23b4779cae468e3497a5ad1f4a1"}], "title": "tcp: challenge ACK for non-exact RST in SYN-RECEIVED", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_input.c", "net/ipv4/tcp_minisocks.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "234f9ffbd9b2c1b24ec67200ea3cff07401bec48", "status": "affected", "version": "282f23c6ee343126156dd41218b22ece96d747e3", "versionType": "git"}, {"lessThan": "22cec809b048495310f206d9abbcdbbfbdce3ae3", "status": "affected", "version": "282f23c6ee343126156dd41218b22ece96d747e3", "versionType": "git"}, {"lessThan": "a28c4fcbf774e23b4779cae468e3497a5ad1f4a1", "status": "affected", "version": "282f23c6ee343126156dd41218b22ece96d747e3", "versionType": "git"}, {"status": "affected", "version": "86791bbfe5ed7b275be040cfeff049a1624af1b7", "versionType": "git"}, {"status": "affected", "version": "61f69dc4e40e41b0018f00fa4aeb23d3239556fb", "versionType": "git"}, {"status": "affected", "version": "34fb350281ced2a72707a5c0064f69992d440edb", "versionType": "git"}, {"lessThan": "3.1", "status": "affected", "version": "3.0.58", "versionType": "semver"}, {"lessThan": "3.3", "status": "affected", "version": "3.2.37", "versionType": "semver"}, {"lessThan": "3.5", "status": "affected", "version": "3.4.25", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["include/net/tcp.h", "net/ipv4/tcp_input.c", "net/ipv4/tcp_minisocks.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "3.6"}, {"lessThan": "3.6", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.42", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.6", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2-rc5", "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: challenge ACK for non-exact RST in SYN-RECEIVED\n\nThe SYN-RECEIVED request-socket path in tcp_check_req() accepts an\nin-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A\nnon-exact RST therefore removes the request instead of eliciting a\nchallenge ACK.\n\nRFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in\nSYN-RECEIVED: an exact RST resets the connection, while a non-exact\nin-window RST must trigger a challenge ACK and be dropped.\n\nApply that check before the ACK-field validation, following the RFC\nsequence-number, RST, then ACK processing order. Factor the per-netns\nchallenge ACK quota out of tcp_send_challenge_ack() so request sockets\ncan share it. Use the request socket's send_ack() callback and its own\nout-of-window ACK timestamp to send and rate-limit the response."}], "id": "CVE-2026-68118", "lastModified": "2026-08-13T23:17:17.007", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 4.2, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-10T13:19:56.850", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/22cec809b048495310f206d9abbcdbbfbdce3ae3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/234f9ffbd9b2c1b24ec67200ea3cff07401bec48"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a28c4fcbf774e23b4779cae468e3497a5ad1f4a1"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Denial of service in TCP connection handling via crafted RST packets", "id": "2513252", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2513252"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-358", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ntcp: challenge ACK for non-exact RST in SYN-RECEIVED\nThe SYN-RECEIVED request-socket path in tcp_check_req() accepts an\nin-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A\nnon-exact RST therefore removes the request instead of eliciting a\nchallenge ACK.\nRFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in\nSYN-RECEIVED: an exact RST resets the connection, while a non-exact\nin-window RST must trigger a challenge ACK and be dropped.\nApply that check before the ACK-field validation, following the RFC\nsequence-number, RST, then ACK processing order. Factor the per-netns\nchallenge ACK quota out of tcp_send_challenge_ack() so request sockets\ncan share it. Use the request socket's send_ack() callback and its own\nout-of-window ACK timestamp to send and rate-limit the response.", "A flaw was found in the Linux kernel's handling of TCP (Transmission Control Protocol) connections. A remote attacker could send a specially crafted TCP Reset (RST) packet during the SYN-RECEIVED state. This could cause the system to prematurely remove connection requests instead of issuing a challenge acknowledgment (ACK), potentially leading to a denial of service (DoS) by disrupting the establishment of new network connections."], "name": "CVE-2026-68118", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:enterprise_linux_nvidia:", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux for NVIDIA 26"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "rhcos", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-08-10T11:58:38Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-68118\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68118\nhttps://git.kernel.org/stable/c/22cec809b048495310f206d9abbcdbbfbdce3ae3\nhttps://git.kernel.org/stable/c/234f9ffbd9b2c1b24ec67200ea3cff07401bec48\nhttps://git.kernel.org/stable/c/a28c4fcbf774e23b4779cae468e3497a5ad1f4a1"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[282f23c6ee343126156dd41218b22ece96d747e3,234f9ffbd9b2c1b24ec67200ea3cff07401bec48)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[282f23c6ee343126156dd41218b22ece96d747e3,22cec809b048495310f206d9abbcdbbfbdce3ae3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[282f23c6ee343126156dd41218b22ece96d747e3,a28c4fcbf774e23b4779cae468e3497a5ad1f4a1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "86791bbfe5ed7b275be040cfeff049a1624af1b7"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "61f69dc4e40e41b0018f00fa4aeb23d3239556fb"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "34fb350281ced2a72707a5c0064f69992d440edb"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.0.58,3.1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.2.37,3.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.4.25,3.5)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "3.6"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,3.6)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.42,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1.6,7.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc5,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-10T15:00:03.566016+00:00", "updated": "2026-08-14T02:00:15.465503+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}