CVE-2025-6499
vstakhov libucl ucl_parser.c ucl_parse_multiline_string heap-based overflow
CVE-2025-6499 is a medium vulnerability (CVSS 4.8) in Libucl, published June 23, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.27%, the 18th percentile. No source names a fixed version.
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
4.8
vstakhov libucl ucl_parser.c ucl_parse_multiline_string heap-based overflow
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
- Record
CVE-2025-6499- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R - CVSS 3.0
- 3.3 Low
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R - CVSS 2.0
- 1.7
AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR - Weakness
- CWE-122, CWE-119
- Updated
- 2026-11-02
EUVDEUVD-2025-28741
4.8
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
- Record
EUVD-2025-28741- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vprg-8xj9-vhmq
1.9
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by...
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
- Record
GHSA-vprg-8xj9-vhmq- CVSS 4.0
- 1.9 Low
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-119, CWE-787
- Updated
- 2026-11-02
NVD
1.9
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
- Record
CVE-2025-6499- CVSS 4.0
- 1.9 Low
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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 - CVSS 3.1
- 3.3 Low
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 1.7 Low
AV:L/AC:L/Au:S/C:N/I:N/A:P - Weakness
- CWE-119, CWE-122, CWE-787
- Updated
- 2026-11-02
OSV
1.9
vstakhov libucl ucl_parser.c ucl_parse_multiline_string heap-based overflow
A vulnerability classified as problematic was found in vstakhov libucl up to 0.9.2. Affected by this vulnerability is the function ucl_parse_multiline_string of the file src/ucl_parser.c. The manipulation leads to heap-based buffer overflow. The attack needs to be approached locally. The exploit has been disclosed to the public and may be used.
- Record
CVE-2025-6499- CVSS 4.0
- 1.9 Low
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P - Weakness
- CWE-119, CWE-122
- Updated
- 2026-11-02
Affected products
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |
References
vuldb.com?id.313615
vuldb.com?ctiid.313615
vuldb.com?submit.601011
github.com/vstakhov/libucl/issues/319
github.com/user-attachments/files/19825399/libucl_crash.txt
nvd.nist.gov/vuln/detail/CVE-2025-6499
github.com/advisories/GHSA-vprg-8xj9-vhmq
github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6499.json