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CVE.org (no NVD analysis yet)· CNA zephyr

CVE-2026-90589: Memory-mapped thread stack is never unmapped when a thread is aborted by another thread, exhausting kernel virtual address space

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.10% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: zephyrproject zephyr 4.3.2, 4.5.0.

Low priority for now. Upgrade to zephyrproject zephyr 4.3.2, 4.5.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

When CONFIG_THREAD_STACK_MEM_MAPPED is enabled, each thread stack is mapped into the kernel virtual address space with a guard page on either side, and the mapping is released during abort cleanup. k_thread_abort_cleanup() in kernel/thread.c has two paths: a deferred one for self-abort, which stashes the mapping in thread_cleanup_stack_addr/thread_cleanup_stack_sz, and an immediate one for a thread aborted by some other thread. The immediate path called do_thread_cleanup(), which ignored its thread argument and only ever unmapped the stashed address — a value populated exclusively by the self-abort path. The mapped stack of a thread aborted by another thread was therefore never unmapped. Every k_thread_abort() of a non-current thread leaks the thread's stack region plus its two guard pages from the kernel virtual address space. Threads that end by returning from their entry function take the working self-abort path, so the leak is specific to explicit cancellation — k_thread_abort(), pthread_cancel(), osThreadTerminate(), or the kernel thread kill shell command. Both k_thread_create() and k_thread_abort() are system calls, so with CONFIG_USERSPACE an unprivileged user-mode thread that has been granted a thread object and a user-capable stack object can drive the leak from user mode, consuming a kernel-side resource it cannot otherwise touch. With CONFIG_KERNEL_VM_SIZE defaulting to 8 MB, a few hundred create/abort cycles exhaust the runtime mapping region. k_mem_map_phys_guard() then returns NULL, and map_thread_stack() guards that only with __ASSERT_NO_MSG(), which is compiled out of production builds; thread creation proceeds to write through a NULL-derived stack base and faults in kernel mode. The impact is a persistent denial of service — a kernel fatal error requiring a reboot — with no memory disclosure or corruption, and it is limited to configurations where memory-mapped thread stacks are enabled (x86 targets with X86_MMU and demand paging disabled, where the option is implied by default).

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Nov 9, 2026
Updated
Nov 9, 2026
EPSS
0.1% · 0th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · zephyr
5.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (zephyr). Independent of NVD's CPE analysis and usually ahead of it.

  • zephyrproject zephyr

    • 3.7.0 and later · before 4.3.2affected · semver
    • 4.4.0 and later · before 4.5.0affected · semver

Same product

zephyrproject: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-4260Potential off-by-one buffer overflow vulnerability in the Zephyr FS subsystem
    40Plan
  • CVE-2021-3625Buffer overflow in Zephyr USB DFU DNLOAD
    40Plan
  • CVE-2020-10071Insufficient publish message length validation in MQTT
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-90587Nov 9, 2026 · NULL pointer dereference in the Zephyr USB host stack when a device reports zero configurations
    18Monitor
  • ← EarlierCVE-2026-90588Nov 9, 2026 · Out-of-bounds read in Zephyr HTTP client debug logging of response header fields
    14Monitor
  • Later →CVE-2026-90590Nov 9, 2026 · Permanent loss of transmit capability in the NXP ENET QoS Ethernet driver after an Ethernet link drop
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
zephyrproject zephyr4.3.2Vendor (CNA)
zephyrproject zephyr4.5.0Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 11, 2026+1 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-870445 days apartMemory leak in the Mbed TLS crypto shim on failed cipher/AEAD operations leads to remotely triggered crypto denial of service
    26Monitor
  • CVE-2026-1973829 days apartRetained RX node leak and reachable assertion in Bluetooth Controller CIS Create procedures
    26Monitor
  • CVE-2026-1973929 days apartBluetooth LE controller leaks a retained RX node when an unexpected LL Control PDU arrives during a Connection Update
    26Monitor
  • CVE-2026-1974029 days apartBluetooth LE Controller: retained RX node leak and reachable assertion in the PHY Update procedure
    26Monitor
  • CVE-2026-1469670 days apartEthernet bridge RX packet leak enables denial of service via RX buffer-pool exhaustion
    26Monitor
  • CVE-2026-1469770 days apartIPv6 Neighbor Solicitation packet leak causes TX pool exhaustion denial of service
    26Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-401 · Missing Release of Memory after Effective Lifetime

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Exploit maturity— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records