FreeRTOS-Kernel: Out-of-bounds Read
CVE-2026-77237 is a high-severity out-of-bounds read vulnerability in FreeRTOS-Kernel from FreeRTOS, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected FreeRTOS-Kernel versions: 7.4.0 through 11.3.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.18% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Freertos to 11.3.1 or a later version.
- Read the advisory on aws.amazon.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| FreeRTOS | FreeRTOS-Kernel | 7.4.0 through 11.3.0 | Not stated |
| Amazon | Freertos | 7.4.0 up to, but not including, 11.3.1 | 11.3.1 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.2 | High | CNA |
| CVSS 3.1 | 6.5 | Medium | CNA |
| CVSS 3.1 | 8.4 | High | NVD |
Official description
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other vulnerabilities in FreeRTOS-Kernel
- 8.8 High severity
- 8.8 High severity
- 7.3 High severity
- 7.3 High severity
- 8.8 High severity
- 7.8 High severity
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.5 High severity
- 9.1 Critical severity
- 9.1 Critical severity
- 7.1 High severity
- 7.5 High severity
Spotted an error? Tell us.