Arm Compiler 5 through 5.06u6 has an error in a stack protection feature designed to help spot stack-based buffer overflows in local arrays.

published 2020-12-24 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-17373

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits: 0; none known

Arm Compiler 5 through 5.06u6 has an error in a stack protection feature designed to help spot stack-based buffer overflows in local arrays. When this feature is enabled, a protected function writes a guard value to the stack prior to (above) any vulnerable arrays in the stack. The guard value is checked for corruption on function return; corruption leads to an error-handler call. In certain circumstances, the reference value that is compared against the guard value is itself also written to the stack (after any vulnerable arrays). The reference value is written to the stack when the function runs out of registers to use for other temporary data. If both the reference value and the guard value are written to the stack, then the stack protection will fail to spot corruption when both values are overwritten with the same value. For both the reference value and the guard value to be corrupted, there would need to be both a buffer overflow and a buffer underflow in the vulnerable arrays (or some other vulnerability that causes two separated stack entries to be corrupted).

Patch / fix

fixed in 1

arm arm_compiler 5.06

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	4.4	AV:L/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-770 Allocation of Resources Without Limits or Throttling
CWE-787 Out-of-bounds Write

References

developer.arm.com /support/arm-security-updates/arm-compiler-5-stack-protection
vendor-advisory

Sources

CVE List CVE-2020-24658
NVD CVE-2020-24658

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Summary