High Memory corruption

CVE-2026-77237 — Missing type validation in xQueueAddToSet in FreeRTOS-Kernel

Missing queue-set type validation in xQueueAddToSet() in the FreeRTOS-Kernel before 11.3.1 might allow an unprivileged task on MPU-enabled ports with configUSE_QUEUE_SETS=1 to read privileged kernel memory. To remediate this issue, users should upgrade to version 11.3.1 or later.

Published Aug 21, 2026 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: AMZN

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 7% of scored CVEs · Oct 14, 2026

Affects

Amazon

Freertos and 1 more

CVSS base

8.4

High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Amazon Freertos, Freertos FreeRTOS-Kernel).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Amazon	Freertos	≥ 7.4.0 and < 11.3.1	Vulnerable	NIST National Vulnerability Database
Freertos	FreeRTOS-Kernel	≥ 7.4.0 and ≤ 11.3.0	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.2	CVSS 4.0	High	—	—	ff89ba41-3aa1-4d27-914a-91399e9639e5 via NIST National Vulnerability Database
8.2	CVSS 4.0	High	—	—	AMZN via CVE Program (cve.org) e CISA ADP
8.4	CVSS 3.1	High	2.0	5.8	nvd@nist.gov via NIST National Vulnerability Database
6.5	CVSS 3.1	Medium	2.0	4.0	ff89ba41-3aa1-4d27-914a-91399e9639e5 via NIST National Vulnerability Database
6.5	CVSS 3.1	Medium	—	—	AMZN via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 8.4 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-125 · Out-of-bounds Read

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · freertos/freertos-kernel
Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 14, 2026
Affected products added · amazon/freertos
Oct 14, 2026 · NIST National Vulnerability Database
CVSS changed · 8.4
Oct 14, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 14, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 14, 2026 · Alertas do Telegram
CVE published
Aug 21, 2026 · AMZN

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 14, 2026 – Oct 14, 2026
1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

3 on the record

github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-9wvc-hqvx-5wf5
Vendor Advisory, third-party-advisory, NIST National Vulnerability Database
aws.amazon.com/security/security-bulletins/2026-086-aws/
Vendor Advisory, vendor-advisory, NIST National Vulnerability Database
github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.1
Release Notes, patch, NIST National Vulnerability Database

Elsewhere on this site

Amazon
every CVE for this vendor

Memory corruption
same class

CWE-125
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-77234 Improper input validation in FreeRTOS-Kernel timer command handling Aug 21, 2026
High CVE-2026-77235 Missing privilege check in SecureContext_FreeContext in FreeRTOS-Kernel Aug 21, 2026
High CVE-2026-77236 Missing size validation in SecureContext_AllocateContext in FreeRTOS-Kernel Aug 21, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-77237 is "Missing type validation in xQueueAddToSet in FreeRTOS-Kernel", rated High. It affects Freertos (Amazon); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.4 describes technical severity. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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