CVE-2019-12495
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source...
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
CVE-2019-12495- CVSS 3.0
- 5.5 Medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-787
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
CVE-2019-12495- Updated
- 2026-11-02
EUVDEUVD-2019-4091 No score
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
EUVD-2019-4091- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pv69-3373-mhhq
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source...
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
GHSA-pv69-3373-mhhq- CVSS 3.0
- 5.5 Medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-787
- Updated
- 2026-11-02
OSV
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
CVE-2019-12495- CVSS 3.0
- 5.5 Medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2019-12495
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
DEBIAN-CVE-2019-12495- CVSS 3.0
- 5.5 Medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2019-12495
An issue was discovered in Tiny C Compiler (aka TinyCC or TCC) 0.9.27. Compiling a crafted source file leads to a one-byte out-of-bounds write in the gsym_addr function in x86_64-gen.c. This occurs because tccasm.c mishandles section switches.
- Record
UBUNTU-CVE-2019-12495- CVSS 3.0
- 5.5 Medium
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
tccDebian:12 |
before 0.9.27+git20200814.62c30a4a-1 | 0.9.27+git20200814.62c30a4a-1 |
tccDebian:13 |
before 0.9.27+git20200814.62c30a4a-1 | 0.9.27+git20200814.62c30a4a-1 |
tccUbuntu:16.04:LTS |
All versions, plus listed versions 0.9.27~git20140923.9d7fb33-3ubuntu10.9.27~git20151227.933c223-1 |
None known |
tccUbuntu:18.04:LTS |
All versions, plus listed versions 0.9.27~git20161217.cd9514ab-3ubuntu10.9.27-20.9.27-40.9.27-5 |
None known |
tccUbuntu:20.04:LTS |
All versions, plus listed versions 0.9.27-8 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2019-12495 is a medium vulnerability (CVSS 5.5) in Tinycc, published May 31, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.22%, the 68th percentile. Fixed in tcc 0.9.27+git20200814.62c30a4a-1.
References
lists.nongnu.org/archive/html/tinycc-devel/2019-05/msg00044.html
repo.or.cz/tinycc.git/commit/d04ce7772c2bc2781ab2502e0b1f1964488814b5
securityfocus.com/bid/108541
nvd.nist.gov/vuln/detail/CVE-2019-12495
github.com/advisories/GHSA-pv69-3373-mhhq
security-tracker.debian.org/tracker/CVE-2019-12495
ubuntu.com/security/CVE-2019-12495
cve.org/CVERecord?id=CVE-2019-12495