CVE-2026-53240

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-53240", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.393Z", "datePublished": "2026-06-25T08:39:35.809Z", "dateUpdated": "2026-08-05T12:34:26.772Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:34:26.772Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix use-after-free on first_skb in __input_process_payload\n\n__input_process_payload() stores first_skb into xtfs->ra_newskb under\ndrop_lock when starting partial reassembly, then unlocks and breaks out\nof the processing loop. The post-loop check reads xtfs->ra_newskb\nwithout the lock to decide whether first_skb is still owned:\n\n if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb)\n\nBetween spin_unlock and this read, a concurrent CPU running\niptfs_reassem_cont() (or the drop_timer hrtimer) can complete\nreassembly, NULL xtfs->ra_newskb, and free the skb. The check then\nevaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb\noperate on the freed skb \u2014 a use-after-free in skbuff_head_cache.\n\nReplace the unlocked read with a local bool that records whether\nfirst_skb was handed to the reassembly state in the current call. The\nflag is set after the existing spin_unlock, before the break, using the\npointer equality that is stable at that point (first_skb == skb iff\nfirst_skb was stored in ra_newskb)."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - The vulnerable IPTFS parser is reached from the network receive path through xfrm4/xfrm6 ESP handling, xfrm_input, and iptfs_input on an inbound IPTFS SA. A reasonable high-impact deployment is an internet-reachable IPsec/IPTFS gateway processing remote peer traffic.\nAC:L - The bug is a use-after-free race after first_skb is handed to reassembly, and the attacker can drive the needed fragmented/reordered IPTFS packets and concurrent continuation processing. There is no condition beyond the attacker\u2019s control once valid IPTFS ESP traffic reaches the SA.\nPR:L - Unauthenticated packets are rejected by XFRM/ESP state lookup, replay, and crypto verification before IPTFS parsing, so a remote attacker needs valid SA access or credentials. Locally, creating the IPTFS SA requires CAP_NET_ADMIN in a network namespace, which is reachable as low privilege via user namespaces.\nUI:N - No victim user action is required after the vulnerable SA is present; packet receipt alone triggers the path. The attacker sends crafted traffic to the configured endpoint.\nS:U - The impact is kernel memory corruption within the same host kernel security authority. This is not a VM escape, IOMMU bypass, or other cross-scope boundary.\nC:H - This is a use-after-free of an sk_buff from skbuff_head_cache, and freed object reuse can expose kernel memory or support stronger disclosure primitives. Under the required guidance, UAF memory corruption warrants high confidentiality impact.\nI:H - The stale sk_buff is subsequently used by pskb_trim, field writes, and freeing paths, giving a plausible route to heap corruption and control-flow or data corruption. Under the required guidance, UAF memory corruption warrants high integrity impact.\nA:H - The stale sk_buff access can corrupt kernel heap state or crash in packet processing/freeing paths. A kernel oops, panic, or repeatable crash is high availability impact."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_iptfs.c"], "versions": [{"version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "lessThan": "8d9a79fbf5172d9c4c0146057af2360913265a11", "status": "affected", "versionType": "git"}, {"version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "lessThan": "ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198", "status": "affected", "versionType": "git"}, {"version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "lessThan": "eb48730bb827d1550401a5d391903f9d90b493c8", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/xfrm/xfrm_iptfs.c"], "versions": [{"version": "6.14", "status": "affected"}, {"version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.36", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.13", "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": "6.14", "versionEndExcluding": "6.18.36"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.0.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8d9a79fbf5172d9c4c0146057af2360913265a11"}, {"url": "https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"}, {"url": "https://git.kernel.org/stable/c/eb48730bb827d1550401a5d391903f9d90b493c8"}], "title": "xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_iptfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8d9a79fbf5172d9c4c0146057af2360913265a11", "status": "affected", "version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "versionType": "git"}, {"lessThan": "ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198", "status": "affected", "version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "versionType": "git"}, {"lessThan": "eb48730bb827d1550401a5d391903f9d90b493c8", "status": "affected", "version": "3f3339885fb343b7b42d7c34717108ce07da24ae", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/xfrm/xfrm_iptfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.14"}, {"lessThan": "6.14", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.36", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.13", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "F44E71B4-36C2-4FDD-9239-2EEBD641A1C8", "versionEndExcluding": "6.18.36", "versionStartIncluding": "6.14", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "6A64BF9F-3BCA-42FD-98CB-8F03474D2B1E", "versionEndExcluding": "7.0.13", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*", "matchCriteriaId": "81DFF19E-9CF8-49C6-8C36-1E4038622933", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:*", "matchCriteriaId": "B0E8FC71-3952-444C-83E9-718DBBBEC615", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc7:*:*:*:*:*:*", "matchCriteriaId": "1039E95A-8CC3-4C88-8FF9-5C08EEB861C9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: fix use-after-free on first_skb in __input_process_payload\n\n__input_process_payload() stores first_skb into xtfs->ra_newskb under\ndrop_lock when starting partial reassembly, then unlocks and breaks out\nof the processing loop. The post-loop check reads xtfs->ra_newskb\nwithout the lock to decide whether first_skb is still owned:\n\n if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb)\n\nBetween spin_unlock and this read, a concurrent CPU running\niptfs_reassem_cont() (or the drop_timer hrtimer) can complete\nreassembly, NULL xtfs->ra_newskb, and free the skb. The check then\nevaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb\noperate on the freed skb \u2014 a use-after-free in skbuff_head_cache.\n\nReplace the unlocked read with a local bool that records whether\nfirst_skb was handed to the reassembly state in the current call. The\nflag is set after the existing spin_unlock, before the break, using the\npointer equality that is stable at that point (first_skb == skb iff\nfirst_skb was stored in ra_newskb)."}], "id": "CVE-2026-53240", "lastModified": "2026-07-08T13:05:31.967", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-06-25T09:16:41.960", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8d9a79fbf5172d9c4c0146057af2360913265a11"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/eb48730bb827d1550401a5d391903f9d90b493c8"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload", "id": "2492761", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2492761"}, "csaw": false, "cwe": "CWE-367", "details": ["A flaw was found in the Linux kernel's xfrm: iptfs component. A race condition during partial packet reassembly in the __input_process_payload() function can lead to a use-after-free vulnerability. This occurs when a concurrent process frees a packet buffer (skb) before it is checked, allowing subsequent operations to access freed memory. This could result in memory corruption."], "name": "CVE-2026-53240", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-06-25T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-53240\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53240\nhttps://lore.kernel.org/linux-cve-announce/2026062511-CVE-2026-53240-542b@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f3339885fb343b7b42d7c34717108ce07da24ae,8d9a79fbf5172d9c4c0146057af2360913265a11)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f3339885fb343b7b42d7c34717108ce07da24ae,ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[3f3339885fb343b7b42d7c34717108ce07da24ae,eb48730bb827d1550401a5d391903f9d90b493c8)"}}], "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": "6.14"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.14)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.36,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.13,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "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": "2026-06-25T12:15:03.846924+00:00", "updated": "2026-08-12T08:15:04.571458+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}