VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98775: Linux kernel · nitro_enclaves: fix use-after-free on SLOT_ALLOC failure

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in f7fb6c2835ede1b8ad84cf7e78a528a9d0159b84 : patch Linux kernel soon.

Data as of 26 Oct 2026, 20:31 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f7fb6c2835ede1b8ad84cf7e78a528a9d0159b84, 466041d14f26dc2babd606a2e85dce08774112a6, 43f78b328f3907ca2f7424e15b7e45ffbf9fe21c +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799, < f7fb6c2835ede1b8ad84cf7e78a528a9d0159b84	Fixed in f7fb6c2835ede1b8ad84cf7e78a528a9d0159b84
LinuxLinux	Affected ≥ 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799, < 466041d14f26dc2babd606a2e85dce08774112a6	Fixed in 466041d14f26dc2babd606a2e85dce08774112a6
LinuxLinux	Affected ≥ 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799, < 43f78b328f3907ca2f7424e15b7e45ffbf9fe21c	Fixed in 43f78b328f3907ca2f7424e15b7e45ffbf9fe21c
LinuxLinux	Affected ≥ 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799, < 9bc184a2eda8b773c88ecbff934001ad649b9cc1	Fixed in 9bc184a2eda8b773c88ecbff934001ad649b9cc1
LinuxLinux	Affected ≥ 9c8eb50fe9e2bb8a2e725979e052fbf592b6b799, < 8bde6f643ab6fe5e3e3f4c312f84ce327ecf39b2	Fixed in 8bde6f643ab6fe5e3e3f4c312f84ce327ecf39b2
LinuxLinux	Affected =5.10	Fixed in–

AI-suggested

A patch is available and has been applied to fix this vulnerability. The fix clears private data before releasing the file on the error path, preventing the use-after-free. Users should update to the fixed Linux kernel versions containing the patch. Since this is a kernel-level issue, applying the official kernel update is the recommended remediation.

Description

CVE-2026-98775 is a use-after-free vulnerability in the Linux kernel's nitro_enclaves component. The flaw occurs when the SLOT_ALLOC request fails during enclave creation, leading to a deferred release function accessing freed memory. This can trigger a kernel address sanitizer (KASAN) slab-use-after-free error. The issue is fixed by clearing private data before releasing the file, preventing the use-after-free condition. The patch does not affect normal enclave creation or teardown.

Impact

This vulnerability causes a use-after-free condition in kernel memory management during enclave creation failure, which can lead to kernel memory corruption and potential system instability or crashes. It is detected by KASAN as a slab-use-after-free error. There is no indication of active exploitation in the wild. The impact is limited to error paths during enclave creation failures and does not affect normal enclave operations.

Summary

The vulnerability in the Linux kernel nitro_enclaves arises when ne_create_vm_ioctl() fails the SLOT_ALLOC request after anon_inode_getfile() succeeds. The error path calls fput(enclave_file) and frees ne_enclave, but due to deferred execution of ne_enclave_release() via task_work, it accesses ne_enclave->slot_uid after ne_enclave has been freed, causing a use-after-free detected by KASAN. The enclave is not linked into the enclave list and has no slot allocated at this point. The fix clears enclave_file->private_data before fput() on the error path, causing ne_enclave_release() to return immediately when private_data is NULL, thus avoiding the use-after-free. Testing on AWS EC2 with KASAN enabled confirms the fix prevents the slab-use-after-free error while preserving error reporting and normal operations.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 20:31 UTC

Technical details

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