{"id":"CVE-2026-23239","state":"PUBLISHED","title":"espintcp: Fix race condition in espintcp_close()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nespintcp: Fix race condition in espintcp_close()\n\nThis issue was discovered during a code audit.\n\nAfter cancel_work_sync() is called from espintcp_close(),\nespintcp_tx_work() can still be scheduled from paths such as\nthe Delayed ACK handler or ksoftirqd.\nAs a result, the espintcp_tx_work() worker may dereference a\nfreed espintcp ctx or sk.\n\nThe following is a simple race scenario:\n\n           cpu0                             cpu1\n\n  espintcp_close()\n    cancel_work_sync(&ctx->work);\n                                     espintcp_write_space()\n                                       schedule_work(&ctx->work);\n\nTo prevent this race condition, cancel_work_sync() is\nreplaced with disable_work_sync().","publishedAt":"2026-03-10T17:28:26.190Z","updatedAt":"2026-10-19T18:35:39.619Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"f7ad8b1d0e421c524604d5076b73232093490d5c","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"664e9df53226b4505a0894817ecad2c610ab11d8","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"022ff7f347588de6e17879a1da6019647b21321b","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"e1512c1db9e8794d8d130addd2615ec27231d994","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/espintcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/espintcp.c"]}],"references":["https://git.kernel.org/stable/c/f7ad8b1d0e421c524604d5076b73232093490d5c","https://git.kernel.org/stable/c/664e9df53226b4505a0894817ecad2c610ab11d8","https://git.kernel.org/stable/c/022ff7f347588de6e17879a1da6019647b21321b","https://git.kernel.org/stable/c/e1512c1db9e8794d8d130addd2615ec27231d994"],"weaknesses":["CWE-362"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/23xxx/CVE-2026-23239.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-23239","state":"PUBLISHED","datePublished":"2026-03-10T17:28:26.190Z","dateUpdated":"2026-10-19T18:35:39.619Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:45.989Z"},"containers":{"cna":{"title":"espintcp: Fix race condition in espintcp_close()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nespintcp: Fix race condition in espintcp_close()\n\nThis issue was discovered during a code audit.\n\nAfter cancel_work_sync() is called from espintcp_close(),\nespintcp_tx_work() can still be scheduled from paths such as\nthe Delayed ACK handler or ksoftirqd.\nAs a result, the espintcp_tx_work() worker may dereference a\nfreed espintcp ctx or sk.\n\nThe following is a simple race scenario:\n\n           cpu0                             cpu1\n\n  espintcp_close()\n    cancel_work_sync(&ctx->work);\n                                     espintcp_write_space()\n                                       schedule_work(&ctx->work);\n\nTo prevent this race condition, cancel_work_sync() is\nreplaced with disable_work_sync()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"f7ad8b1d0e421c524604d5076b73232093490d5c","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"664e9df53226b4505a0894817ecad2c610ab11d8","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"022ff7f347588de6e17879a1da6019647b21321b","versionType":"git"},{"version":"e27cca96cd68fa2c6814c90f9a1cfd36bb68c593","status":"affected","lessThan":"e1512c1db9e8794d8d130addd2615ec27231d994","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/espintcp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.6","versionType":"semver"},{"version":"6.12.75","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/espintcp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f7ad8b1d0e421c524604d5076b73232093490d5c"},{"url":"https://git.kernel.org/stable/c/664e9df53226b4505a0894817ecad2c610ab11d8"},{"url":"https://git.kernel.org/stable/c/022ff7f347588de6e17879a1da6019647b21321b"},{"url":"https://git.kernel.org/stable/c/e1512c1db9e8794d8d130addd2615ec27231d994"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The attacker must be a local user to create a TCP socket and set the espintcp ULP via setsockopt(TCP_ULP). This cannot be triggered remotely without local socket access.\nAC:L - The attacker controls both sides of the race: they trigger close() and control the remote peer (e.g., localhost connection) to send TCP ACKs that fire write_space, reliably creating the race condition.\nPR:L - No capability checks exist in the TCP_ULP setsockopt path or espintcp_init_sk(). Any unprivileged local user can set up an espintcp ULP socket and trigger this bug.\nUI:N - No user interaction is required; the attacker autonomously creates the socket, sets the ULP, and triggers the race.\nS:U - The vulnerability is a kernel-level use-after-free that does not cross a security boundary such as a VM or sandbox.\nC:H - The use-after-free on espintcp_ctx and sock structures allows an attacker to control freed object contents via heap spraying, enabling arbitrary kernel memory reads.\nI:H - The use-after-free enables heap spraying and arbitrary write primitives through the freed espintcp_ctx and sock structures, allowing potential kernel code execution.\nA:H - The use-after-free causes kernel crashes (oops/panic) when the work function dereferences freed memory, providing reliable denial of service."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:20:49.864Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.12.75"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-23239","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:06:50.245175Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-362","lang":"en","type":"CWE","description":"CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T18:35:39.619Z"}}]}}}