CVE-2021-26706

CVE-2021-26706 is a critical-severity vulnerability in Micrium Uc/lib with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-190.

Key facts

Description

An issue was discovered in lib_mem.c in Micrium uC/OS uC/LIB 1.38.x and 1.39.00. The following memory allocation functions do not check for integer overflow when allocating a pool whose size exceeds the address space: Mem_PoolCreate, Mem_DynPoolCreate, and Mem_DynPoolCreateHW. Because these functions use multiplication to calculate the pool sizes, the operation may cause an integer overflow if the arguments are large enough. The resulting memory pool will be smaller than expected and may be exploited by an attacker.

Frequently asked questions

What is CVE-2021-26706?
An issue was discovered in lib_mem.c in Micrium uC/OS uC/LIB 1.38.x and 1.39.00. The following memory allocation functions do not check for integer overflow when allocating a pool whose size exceeds the address space: Mem_PoolCreate, Mem_DynPoolCreate, and Mem_DynPoolCreateHW. Because these functions use multiplication to calculate the pool sizes, the operation may cause an integer overflow if the arguments are large enough. The resulting memory pool will be smaller than expected and may be exploited by an attacker.
How severe is CVE-2021-26706?
CVE-2021-26706 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26706 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26706?
CVE-2021-26706 primarily affects Micrium Uc/lib. In total, 7 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-26706?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-26706 published?
CVE-2021-26706 was published on 2022-01-24 and last updated on 2026-06-17.

References

Affected products (7)

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