CWE-362
Allowed-with-ReviewConcurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Abstraction: Class · Status: Draft
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
3560 vulnerabilities reference this CWE, most recent first.
GHSA-2GP6-HHCQ-R4R4
Vulnerability from github – Published: 2022-08-10 00:00 – Updated: 2022-08-10 00:00Windows Secure Socket Tunneling Protocol (SSTP) Remote Code Execution Vulnerability. This CVE ID is unique from CVE-2022-34714, CVE-2022-35745, CVE-2022-35752, CVE-2022-35753, CVE-2022-35766, CVE-2022-35767, CVE-2022-35794.
{
"affected": [],
"aliases": [
"CVE-2022-34702"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-08-09T20:15:00Z",
"severity": "HIGH"
},
"details": "Windows Secure Socket Tunneling Protocol (SSTP) Remote Code Execution Vulnerability. This CVE ID is unique from CVE-2022-34714, CVE-2022-35745, CVE-2022-35752, CVE-2022-35753, CVE-2022-35766, CVE-2022-35767, CVE-2022-35794.",
"id": "GHSA-2gp6-hhcq-r4r4",
"modified": "2022-08-10T00:00:18Z",
"published": "2022-08-10T00:00:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-34702"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-34702"
},
{
"type": "WEB",
"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-34702"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2GRH-HM3W-W7HV
Vulnerability from github – Published: 2021-08-25 20:55 – Updated: 2023-06-13 22:08When aborting a task with JoinHandle::abort, the future is dropped in the thread calling abort if the task is not currently being executed. This is incorrect for tasks spawned on a LocalSet. This can easily result in race conditions as many projects use Rc or RefCell in their Tokio tasks for better performance.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "tokio"
},
"ranges": [
{
"events": [
{
"introduced": "1.8.0"
},
{
"fixed": "1.8.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "tokio"
},
"ranges": [
{
"events": [
{
"introduced": "1.7.0"
},
{
"fixed": "1.7.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "tokio"
},
"ranges": [
{
"events": [
{
"introduced": "1.6.0"
},
{
"fixed": "1.6.3"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "tokio"
},
"ranges": [
{
"events": [
{
"introduced": "0.3.0"
},
{
"fixed": "1.5.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-38191"
],
"database_specific": {
"cwe_ids": [
"CWE-362",
"CWE-366"
],
"github_reviewed": true,
"github_reviewed_at": "2021-08-18T21:30:23Z",
"nvd_published_at": "2021-08-08T06:15:00Z",
"severity": "MODERATE"
},
"details": "When aborting a task with JoinHandle::abort, the future is dropped in the thread calling abort if the task is not currently being executed. This is incorrect for tasks spawned on a LocalSet. This can easily result in race conditions as many projects use Rc or RefCell in their Tokio tasks for better performance.",
"id": "GHSA-2grh-hm3w-w7hv",
"modified": "2023-06-13T22:08:56Z",
"published": "2021-08-25T20:55:51Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-38191"
},
{
"type": "WEB",
"url": "https://github.com/tokio-rs/tokio/issues/3929"
},
{
"type": "PACKAGE",
"url": "https://github.com/tokio-rs/tokio"
},
{
"type": "WEB",
"url": "https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/tokio/RUSTSEC-2021-0072.md"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2021-0072.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Race condition in tokio"
}
GHSA-2GV9-7823-FXFM
Vulnerability from github – Published: 2026-09-25 12:31 – Updated: 2026-10-03 12:31In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix race condition during device registration
In hci_register_dev(), the power_on work item is queued to hdev->req_workqueue before initializing hdev->adv_monitors_idr and registering the MSFT extension via msft_register(). For devices marked with quirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on the device. When the power_on work item runs concurrently on another CPU, hci_power_on() detects that the device is unconfigured and immediately invokes hci_dev_do_close(), which calls msft_do_close().
Concurrently, msft_register() allocates the msft structure and exposes it to hdev->msft_data prior to calling mutex_init(&msft->filter_lock). If msft_do_close() executes while hdev->msft_data is already assigned but the mutex has not yet been initialized, mutex_lock(&msft->filter_lock) operates on an uninitialized mutex, triggering a DEBUG_LOCKS warning:
DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline] WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821 ... Call Trace: msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693 hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522 hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0x92d/0xe10 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Fix this by moving the queue_work() call in hci_register_dev() to after idr_init(&hdev->adv_monitors_idr) and msft_register(hdev) so that device structures and extensions are fully initialized before asynchronous tasks can access them. Additionally, assign hdev->msft_data in msft_register() only after mutex_init(&msft->filter_lock) has completed.
{
"affected": [],
"aliases": [
"CVE-2026-98109"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-25T11:17:41Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Fix race condition during device registration\n\nIn hci_register_dev(), the power_on work item is queued to\nhdev-\u003ereq_workqueue before initializing hdev-\u003eadv_monitors_idr and\nregistering the MSFT extension via msft_register(). For devices marked with\nquirks such as HCI_QUIRK_RAW_DEVICE, the HCI_UNCONFIGURED flag is set on\nthe device. When the power_on work item runs concurrently on another CPU,\nhci_power_on() detects that the device is unconfigured and immediately\ninvokes hci_dev_do_close(), which calls msft_do_close().\n\nConcurrently, msft_register() allocates the msft structure and exposes it\nto hdev-\u003emsft_data prior to calling mutex_init(\u0026msft-\u003efilter_lock). If\nmsft_do_close() executes while hdev-\u003emsft_data is already assigned but the\nmutex has not yet been initialized, mutex_lock(\u0026msft-\u003efilter_lock) operates\non an uninitialized mutex, triggering a DEBUG_LOCKS warning:\n\nDEBUG_LOCKS_WARN_ON(lock-\u003emagic != lock)\nWARNING: kernel/locking/mutex.c:625 at __mutex_lock_common\nkernel/locking/mutex.c:625 [inline]\nWARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550\nkernel/locking/mutex.c:821\n...\nCall Trace:\n \u003cTASK\u003e\n msft_do_close+0x308/0x7b0 net/bluetooth/msft.c:693\n hci_dev_close_sync+0x86b/0x10a0 net/bluetooth/hci_sync.c:5522\n hci_dev_do_close net/bluetooth/hci_core.c:499 [inline]\n hci_power_on+0x32c/0x750 net/bluetooth/hci_core.c:937\n process_one_work kernel/workqueue.c:3322 [inline]\n process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n worker_thread+0x92d/0xe10 kernel/workqueue.c:3486\n kthread+0x388/0x470 kernel/kthread.c:436\n ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245\n \u003c/TASK\u003e\n\nFix this by moving the queue_work() call in hci_register_dev() to after\nidr_init(\u0026hdev-\u003eadv_monitors_idr) and msft_register(hdev) so that device\nstructures and extensions are fully initialized before asynchronous tasks\ncan access them. Additionally, assign hdev-\u003emsft_data in msft_register()\nonly after mutex_init(\u0026msft-\u003efilter_lock) has completed.",
"id": "GHSA-2gv9-7823-fxfm",
"modified": "2026-10-03T12:31:27Z",
"published": "2026-09-25T12:31:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98109"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/57938bbdb9bf7fd41cbd5cd509ec10c4b22bec18"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/593e64f64a20b25e4042c3ee863119eb7f991785"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a11ebe8dc0333fb870bbbb656b34690e87ee3f98"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b1faf348c29e6f8302ec7769cbf1c1ef05be014f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d427b1c71d9798083e954d3c13469dc0a2305868"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2H34-5Q7Q-G4H6
Vulnerability from github – Published: 2023-07-13 00:30 – Updated: 2024-04-04 06:05In startInput of AudioPolicyInterfaceImpl.cpp, there is a possible way of erroneously displaying the microphone privacy indicator due to a race condition. This could lead to false user expectations. User interaction is needed for exploitation.
{
"affected": [],
"aliases": [
"CVE-2023-21262"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-07-13T00:15:24Z",
"severity": "LOW"
},
"details": "In startInput of AudioPolicyInterfaceImpl.cpp, there is a possible way of erroneously displaying the microphone privacy indicator due to a race condition. This could lead to false user expectations. User interaction is needed for exploitation.\n\n",
"id": "GHSA-2h34-5q7q-g4h6",
"modified": "2024-04-04T06:05:33Z",
"published": "2023-07-13T00:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-21262"
},
{
"type": "WEB",
"url": "https://android.googlesource.com/platform/frameworks/av/+/2c8973c39478cd3c8cf11d9f27cc0556a106d006"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2023-07-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-2H57-5PPX-7X34
Vulnerability from github – Published: 2026-04-14 18:30 – Updated: 2026-04-14 18:30Use after free in Windows Speech Brokered Api allows an authorized attacker to elevate privileges locally.
{
"affected": [],
"aliases": [
"CVE-2026-32089"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-14T18:17:13Z",
"severity": "HIGH"
},
"details": "Use after free in Windows Speech Brokered Api allows an authorized attacker to elevate privileges locally.",
"id": "GHSA-2h57-5ppx-7x34",
"modified": "2026-04-14T18:30:40Z",
"published": "2026-04-14T18:30:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32089"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32089"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2H5Q-W7WV-63R9
Vulnerability from github – Published: 2025-11-19 12:30 – Updated: 2025-11-19 12:30An attacker with a Looker Developer role could manipulate a LookML project to exploit a race condition during Git directory deletion, leading to arbitrary command execution on the Looker instance.
Looker-hosted and Self-hosted were found to be vulnerable. This issue has already been mitigated for Looker-hosted instances. No user action is required for these.
Self-hosted instances must be upgraded as soon as possible. This vulnerability has been patched in all supported versions of Self-hosted. The versions below have all been updated to protect from this vulnerability. You can download these versions at the Looker download page https://download.looker.com/ : * 24.12.103+ * 24.18.195+ * 25.0.72+ * 25.6.60+ * 25.8.42+ * 25.10.22+
{
"affected": [],
"aliases": [
"CVE-2025-12472"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-11-19T11:15:44Z",
"severity": "HIGH"
},
"details": "An attacker with a Looker Developer role could manipulate a LookML project to exploit a race condition during Git directory deletion, leading to arbitrary command execution on the Looker instance.\n\n\n\nLooker-hosted and Self-hosted were found to be vulnerable.\nThis issue has already been mitigated for Looker-hosted instances.\u00a0No user action is required for these.\n\n\nSelf-hosted instances must be upgraded as soon as possible. This vulnerability has been patched in all supported versions of Self-hosted.\nThe versions below have all been updated to protect from this vulnerability. You can download these versions at the Looker download page https://download.looker.com/ :\n * 24.12.103+\n * 24.18.195+\n * 25.0.72+\n * 25.6.60+\n * 25.8.42+\n * 25.10.22+",
"id": "GHSA-2h5q-w7wv-63r9",
"modified": "2025-11-19T12:30:21Z",
"published": "2025-11-19T12:30:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-12472"
},
{
"type": "WEB",
"url": "https://cloud.google.com/support/bulletins#gcp-2025-052"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Red",
"type": "CVSS_V4"
}
]
}
GHSA-2H72-2HX7-MMCQ
Vulnerability from github – Published: 2022-05-24 19:12 – Updated: 2022-07-13 00:01grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.
{
"affected": [],
"aliases": [
"CVE-2021-28697"
],
"database_specific": {
"cwe_ids": [
"CWE-269",
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-08-27T19:15:00Z",
"severity": "HIGH"
},
"details": "grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.",
"id": "GHSA-2h72-2hx7-mmcq",
"modified": "2022-07-13T00:01:15Z",
"published": "2022-05-24T19:12:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-28697"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202208-23"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2021/dsa-4977"
},
{
"type": "WEB",
"url": "https://xenbits.xenproject.org/xsa/advisory-379.txt"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2HGP-6JC7-J8CP
Vulnerability from github – Published: 2022-05-17 02:33 – Updated: 2022-05-17 02:33In TrustZone a time-of-check time-of-use race condition could potentially exist in an authentication routine in all Android releases from CAF using the Linux kernel.
{
"affected": [],
"aliases": [
"CVE-2014-9936"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-05-16T14:29:00Z",
"severity": "HIGH"
},
"details": "In TrustZone a time-of-check time-of-use race condition could potentially exist in an authentication routine in all Android releases from CAF using the Linux kernel.",
"id": "GHSA-2hgp-6jc7-j8cp",
"modified": "2022-05-17T02:33:14Z",
"published": "2022-05-17T02:33:14Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2014-9936"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2017-04-01"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/97329"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1038201"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2HGR-PRP4-CR9P
Vulnerability from github – Published: 2025-01-28 21:31 – Updated: 2025-01-28 21:31In RGXMMUCacheInvalidate of rgxmem.c, there is a possible arbitrary code execution due to a race condition. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.
{
"affected": [],
"aliases": [
"CVE-2024-34732"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-01-28T20:15:30Z",
"severity": "HIGH"
},
"details": "In RGXMMUCacheInvalidate of rgxmem.c, there is a possible arbitrary code execution due to a race condition. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.",
"id": "GHSA-2hgr-prp4-cr9p",
"modified": "2025-01-28T21:31:03Z",
"published": "2025-01-28T21:31:03Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-34732"
},
{
"type": "WEB",
"url": "https://source.android.com/security/bulletin/2024-10-01"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-2HW9-MC66-JC2Q
Vulnerability from github – Published: 2026-10-02 22:45 – Updated: 2026-10-02 22:45Impact
Wasmtime's implementation of bulk-data-transfer WebAssembly instructions, such as memory.copy, contains a vulnerability when a preemption via epochs or fuel is combined with altering the store's state or cancelling a computation. To prevent these operations from taking too long Wasmtime injects fuel/epoch checks during these operations, but this enables embedders, and possible WebAssembly, to witness intermediate state in the middle of the operation. Examples of this include:
- When a non-nullable WebAssembly table is grown the new elements initially start as null and are filled in as part of a loop with preemption checks. If this computation is then cancelled this left the table in a grown-but-uninitialized state where subsequent usage via WebAssembly could possibly segfault. Loads from this table are assumed to not be null due to its type, but the runtime implementation was exposed through this cancellation at a preemption point.
- Embedders could mutate the store during an epoch callback, such as growing a WebAssembly linear memory. During a bulk
memory.copyoperation, however, the pointers being copied to/from weren't recomputed between preemption points. This meant that if the linear memory moved its base address it could be possible to have a preemption, the embedder manually grows memory, and then on resumption the copy operation uses invalid pointers. - Embedders could execute a GC during epoch callbacks. GC operations such as
array.copy, likememory.copyabove, maintained raw pointers internally in the operation which were not updated after the preemption point. This could lead to corruption of the GC heap.
All of these situations are examples of embedder-driven mutations of the Store or embedder-induced resumption of a Store after a computation was cancelled. These operations expose the internal state of these WebAssembly operations which is semantically incorrect and additionally can cause segfaults for example. Exposing these bugs, however, requires explicit patterns to be present in the embedding itself such as using Store::epoch_deadline_callback and mutating wasm options. Another example is to cancel one invocation (possibly in a table.grow) and then execute more wasm afterwards within the same store. Embeddings not using Store::epoch_deadline_callback or executing code after timeouts/fuel are not affected by this issue.
Patches
This issue is fixed in Wasmtime 46.0.2 and 47.0.3. In these versions Wasmtime reverts back to Wasmtime 45-and-earlier behavior for these operations to check fuel once before the operation and then not during the operation. This means that a very large memory.copy does not have preemption points in the middle of the operation any more, for example.
Workarounds
Embedders using Store::epoch_deadline_callback are safe if they only access the T in Store<T>. Embedders that do not continue using a store after a timeout or epoch deadline are also unaffected. Embedders which explicitly mutate the store in an epoch callback, or resume wasm after trapping have no workaround however. The embedding needs to be updated to account for this issue.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "wasmtime"
},
"ranges": [
{
"events": [
{
"introduced": "46.0.0"
},
{
"fixed": "46.0.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "crates.io",
"name": "wasmtime"
},
"ranges": [
{
"events": [
{
"introduced": "47.0.0"
},
{
"fixed": "47.0.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-104855"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-02T22:45:29Z",
"nvd_published_at": "2026-10-02T18:17:02Z",
"severity": "LOW"
},
"details": "### Impact\n\nWasmtime\u0027s implementation of bulk-data-transfer WebAssembly instructions, such as `memory.copy`, contains a vulnerability when a preemption via epochs or fuel is combined with altering the store\u0027s state or cancelling a computation. To prevent these operations from taking too long Wasmtime injects fuel/epoch checks during these operations, but this enables embedders, and possible WebAssembly, to witness intermediate state in the middle of the operation. Examples of this include:\n\n* When a non-nullable WebAssembly table is grown the new elements initially start as null and are filled in as part of a loop with preemption checks. If this computation is then cancelled this left the table in a grown-but-uninitialized state where subsequent usage via WebAssembly could possibly segfault. Loads from this table are assumed to not be null due to its type, but the runtime implementation was exposed through this cancellation at a preemption point.\n* Embedders could mutate the store during an epoch callback, such as growing a WebAssembly linear memory. During a bulk `memory.copy` operation, however, the pointers being copied to/from weren\u0027t recomputed between preemption points. This meant that if the linear memory moved its base address it could be possible to have a preemption, the embedder manually grows memory, and then on resumption the copy operation uses invalid pointers.\n* Embedders could execute a GC during epoch callbacks. GC operations such as `array.copy`, like `memory.copy` above, maintained raw pointers internally in the operation which were not updated after the preemption point. This could lead to corruption of the GC heap.\n\nAll of these situations are examples of embedder-driven mutations of the `Store` or embedder-induced resumption of a `Store` after a computation was cancelled. These operations expose the internal state of these WebAssembly operations which is semantically incorrect and additionally can cause segfaults for example. Exposing these bugs, however, requires explicit patterns to be present in the embedding itself such as using `Store::epoch_deadline_callback` and mutating wasm options. Another example is to cancel one invocation (possibly in a `table.grow`) and then execute more wasm afterwards within the same store. Embeddings not using `Store::epoch_deadline_callback` or executing code after timeouts/fuel are not affected by this issue.\n\n### Patches\n\nThis issue is fixed in Wasmtime 46.0.2 and 47.0.3. In these versions Wasmtime reverts back to Wasmtime 45-and-earlier behavior for these operations to check fuel once before the operation and then not during the operation. This means that a very large `memory.copy` does not have preemption points in the middle of the operation any more, for example.\n\n### Workarounds\n\nEmbedders using `Store::epoch_deadline_callback` are safe if they only access the `T` in `Store\u003cT\u003e`. Embedders that do not continue using a store after a timeout or epoch deadline are also unaffected. Embedders which explicitly mutate the store in an epoch callback, or resume wasm after trapping have no workaround however. The embedding needs to be updated to account for this issue.",
"id": "GHSA-2hw9-mc66-jc2q",
"modified": "2026-10-02T22:45:29Z",
"published": "2026-10-02T22:45:29Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-2hw9-mc66-jc2q"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-104855"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/pull/14041"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/pull/14043"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/pull/14045"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/commit/3ebfbe5af4927c157d6fcaca42b8dbb6d17b73fb"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/commit/99b0bc39d447317a4102c056081c83a9a84a46e0"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/commit/a3eb27af01ba5a30320a90ea1405059cdfedd353"
},
{
"type": "PACKAGE",
"url": "https://github.com/bytecodealliance/wasmtime"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v46.0.2"
},
{
"type": "WEB",
"url": "https://github.com/bytecodealliance/wasmtime/releases/tag/v47.0.3"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2026-0223.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Wasmtime: Preemption and traps during bulk operations enable breaking internal VM state"
}
Mitigation
In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
Mitigation
Use thread-safe capabilities such as the data access abstraction in Spring.
Mitigation
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
- Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Mitigation
When using multithreading and operating on shared variables, only use thread-safe functions.
Mitigation
Use atomic operations on shared variables. Be wary of innocent-looking constructs such as "x++". This may appear atomic at the code layer, but it is actually non-atomic at the instruction layer, since it involves a read, followed by a computation, followed by a write.
Mitigation
Use a mutex if available, but be sure to avoid related weaknesses such as CWE-412.
Mitigation
Avoid double-checked locking (CWE-609) and other implementation errors that arise when trying to avoid the overhead of synchronization.
Mitigation
Disable interrupts or signals over critical parts of the code, but also make sure that the code does not go into a large or infinite loop.
Mitigation
Use the volatile type modifier for critical variables to avoid unexpected compiler optimization or reordering. This does not necessarily solve the synchronization problem, but it can help.
Mitigation MIT-17
Strategy: Environment Hardening
Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
CAPEC-26: Leveraging Race Conditions
The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.
CAPEC-29: Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. A typical example is file access. The adversary can leverage a file access race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary could replace or modify the file, causing the application to behave unexpectedly.