PatchTheCVECVE-2023-4039: **DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains that target AArch64 allows an
CVE-2023-4039 is a medium-severity flaw (CVSS 4.8) affecting gcc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
**DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains that target AArch64 allows an attacker to exploit an existing buffer overflow in dynamically-sized local variables in your application without this being detected. This stack-protector failure only applies to C99-style dynamically-sized local variables or those created using alloca(). The stack-protector operates as intended for statically-sized local variables.
Why this priority
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Risk facts
| CVSS score | 4.8 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 36%) |
| CISA exploited list | No |
| Weakness | CWE-693 |
| Published | 2023-09-13 |
| Last modified | 2026-10-14 |
Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2023-4039?
gcc: upgrade to 2023-09-12. Exact commands for each OS are on this page.
Is CVE-2023-4039 being exploited?
CVE-2023-4039 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2023-4039 affect?
CVE-2023-4039 affects gcc. Severity is medium (CVSS 4.8). **DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains that target AArch64 allows an attacker to exploit an existing buffer overflow in dynamically-sized local variables in your application without this being dete
How urgent is CVE-2023-4039?
Priority 43/100. Public exploit reference; Remotely exploitable, no login, no user action
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