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CVE-2026-23239 (GCVE-0-2026-23239)

Vulnerability from cvelistv5 – Published: 2026-03-10 17:28 – Updated: 2026-08-05 12:20
VLAI
Title
espintcp: Fix race condition in espintcp_close()
Summary
In the Linux kernel, the following vulnerability has been resolved: espintcp: Fix race condition in espintcp_close() This issue was discovered during a code audit. After cancel_work_sync() is called from espintcp_close(), espintcp_tx_work() can still be scheduled from paths such as the Delayed ACK handler or ksoftirqd. As a result, the espintcp_tx_work() worker may dereference a freed espintcp ctx or sk. The following is a simple race scenario: cpu0 cpu1 espintcp_close() cancel_work_sync(&ctx->work); espintcp_write_space() schedule_work(&ctx->work); To prevent this race condition, cancel_work_sync() is replaced with disable_work_sync().
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < f7ad8b1d0e421c524604d5076b73232093490d5c (git)
Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 664e9df53226b4505a0894817ecad2c610ab11d8 (git)
Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < 022ff7f347588de6e17879a1da6019647b21321b (git)
Affected: e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 , < e1512c1db9e8794d8d130addd2615ec27231d994 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.6
Unaffected: 0 , < 5.6 (semver)
Unaffected: 6.12.75 , ≤ 6.12.* (semver)
Unaffected: 6.18.16 , ≤ 6.18.* (semver)
Unaffected: 6.19.6 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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          "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(\u0026ctx-\u003ework);\n                                     espintcp_write_space()\n                                       schedule_work(\u0026ctx-\u003ework);\n\nTo prevent this race condition, cancel_work_sync() is\nreplaced with disable_work_sync()."
        }
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      "metrics": [
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
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              "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."
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        "shortName": "Linux"
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    "dateReserved": "2026-01-13T15:37:45.989Z",
    "dateUpdated": "2026-08-05T12:20:49.864Z",
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      "date": "2026-09-16",
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    },
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      "cve": "CVE-2026-23239",
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      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
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      "title": "espintcp: Fix race condition in espintcp_close()",
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      "version": "2"
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    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23239\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-03-10T18:18:13.383\",\"lastModified\":\"2026-06-17T10:21:09.960\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"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(\u0026ctx-\u003ework);\\n                                     espintcp_write_space()\\n                                       schedule_work(\u0026ctx-\u003ework);\\n\\nTo prevent this race condition, cancel_work_sync() is\\nreplaced with disable_work_sync().\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\\n\\nespintcp: Correcci\u00f3n de condici\u00f3n de carrera en espintcp_close()\\n\\nEste problema fue descubierto durante una auditor\u00eda de c\u00f3digo.\\n\\nDespu\u00e9s de que se llama a cancel_work_sync() desde espintcp_close(), espintcp_tx_work() a\u00fan puede ser programado desde rutas como el gestor de ACK Retrasado o ksoftirqd.\\nComo resultado, el trabajador espintcp_tx_work() puede desreferenciar un ctx o sk de espintcp liberado.\\n\\nEl siguiente es un escenario de condici\u00f3n de carrera simple:\\n\\n           cpu0                             cpu1\\n\\n  espintcp_close()\\n    cancel_work_sync(\u0026amp;ctx-\u0026gt;work);\\n                                     espintcp_write_space()\\n                                       schedule_work(\u0026amp;ctx-\u0026gt;work);\\n\\nPara prevenir esta condici\u00f3n de carrera, cancel_work_sync() es reemplazado por 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      "cve": "CVE-2026-23239",
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      "product_status:recommended": "476",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-23239",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-23239.json",
      "version": "32"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


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