CVE-2026-77237: amazon freertos Out-of-bounds Read
CVSS: 8.4v3.1HighAnalyzed
Published 21-08-2026Last modified 21-08-2026
Vulnerability summary
CVE-2026-77237 is a high (CVSS 8.4) Out-of-bounds Read vulnerability in amazon freertos. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.6% of scored vulnerabilities.
CVSS score
8.4/10
010
High · v3.1 (NVD)EPSS score
0.18%
0%100%
Low · +0.04 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 21-08-2026PublishedVulnerability first disclosed.
- 21-08-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
4 scores · 2 sources · 2 versionsHigh 8.2Preferred score · CVE.org (CNA)
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:NSourcesAll 2 agree
- NVDNIST8.2HighCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/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:X
High 8.4Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:HSources2 sources · 6.5–8.4
- CVE.orgCNA6.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:NDiffers
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
+0.04 pp
From 0.13% on 19-09-2026
19-09-202619-10-2026
EPSS score0.18%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
- CWE-843Access of Resource Using Incompatible Type ('Type Confusion')The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
Affected systems
Amazon1 product
- freertos≥ 7.4.0, < 11.3.1
Freertos1 product
- freertos-kernel≥ 7.4.0, ≤ 11.3.0
2 vendors · 2 products
References
3 links- aws.amazon.com/security/security-bulletins/2026-086-aws/Vendor Advisory
- github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-9wvc-hqvx-5wf5Third Party AdvisoryVendor Advisory