CVE-2026-50643
Out‑of‑Bounds Read in 8cc
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU linemarkers. The compiler accepts attacker-controlled filename and line number metadata and later uses it without validation when accessing source line arrays. By supplying invalid or oversized line numbers, an attacker can trigger out-of-bounds memory access and a crash.
Maintainer of this project was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Version corresponding to the commit b480958 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.1
Out‑of‑Bounds Read in 8cc
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU linemarkers. The compiler accepts attacker-controlled filename and line number metadata and later uses it without validation when accessing source line arrays. By supplying invalid or oversized line numbers, an attacker can trigger out-of-bounds memory access and a crash.
Maintainer of this project was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Version corresponding to the commit b480958 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
- Record
CVE-2026-50643- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2026-37865
5.1
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU linemarkers. The compiler accepts attacker-controlled filename and line number metadata and later uses it without validation when accessing source line arrays. By supplying invalid or oversized line numbers, an attacker can trigger out-of-bounds memory access and a crash.
Maintainer of this project was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Version corresponding to the commit b480958 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
- Record
EUVD-2026-37865- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r8v3-j8rv-hmxv
5.1
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU...
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU linemarkers. The compiler accepts attacker-controlled filename and line number metadata and later uses it without validation when accessing source line arrays. By supplying invalid or oversized line numbers, an attacker can trigger out-of-bounds memory access and a crash.
Maintainer of this project was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Version corresponding to the commit b480958 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
- Record
GHSA-r8v3-j8rv-hmxv- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/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 - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
5.1
8cc is vulnerable to an Out‑of‑Bounds Read due to improper handling of #line directives and GNU linemarkers. The compiler accepts attacker-controlled filename and line number metadata and later uses it without validation when accessing source line arrays. By supplying invalid or oversized line numbers, an attacker can trigger out-of-bounds memory access and a crash.
Maintainer of this project was notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Version corresponding to the commit b480958 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
- Record
CVE-2026-50643- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/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 - Weakness
- CWE-125
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-50643 is a medium vulnerability (CVSS 5.1) in Rui314 8cc, published June 18, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.14%, the 3rd percentile. No source names a fixed version.