CVE-2019-20394
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type...
CVE-2019-20394 is a high vulnerability (CVSS 8.8) in Cesnet Libyang, published January 22, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.81%, the 86th percentile. Fixed in libyang 1.0.184-1.el8.
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
CVE-2019-20394- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:P - Weakness
- CWE-415
- Updated
- 2026-11-02
CVE List No score
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
CVE-2019-20394- Updated
- 2026-11-02
EUVDEUVD-2019-10944 No score
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
EUVD-2019-10944- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pgmh-hmfg-8gwj
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type...
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
GHSA-pgmh-hmfg-8gwj- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Weakness
- CWE-415
- Updated
- 2026-11-02
OSV
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
CVE-2019-20394- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2019-20394
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
DEBIAN-CVE-2019-20394- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVRHEA-2021:1906
Red Hat Enhancement Advisory: libyang bug fix and enhancement update
- Record
RHEA-2021:1906- CVSS 3.1
- 7.0 High
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2019-20394
A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.
- Record
UBUNTU-CVE-2019-20394- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVALEA-2021:1906 No score
libyang bug fix and enhancement update
For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.
- Record
ALEA-2021:1906- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libyangAlmaLinux:8 |
before 1.0.184-1.el8 | 1.0.184-1.el8 |
libyangDebian:13 |
before 1.0.176-1 | 1.0.176-1 |
libyangDebian:14 |
before 1.0.176-1 | 1.0.176-1 |
libyangDebian:10 |
before 0.16.105+really1.0-0+deb10u1, plus listed versions 0.16.105-10.16.105-1+deb10u10.16.105-20.16.105-3 |
0.16.105+really1.0-0+deb10u1 |
libyangRed Hat:enterprise_linux:8::appstream |
before 0:1.0.184-1.el8 | 0:1.0.184-1.el8 |
libyang-cpp-debuginfoRed Hat:enterprise_linux:8::appstream |
before 0:1.0.184-1.el8 | 0:1.0.184-1.el8 |
libyang-debuginfoRed Hat:enterprise_linux:8::appstream |
before 0:1.0.184-1.el8 | 0:1.0.184-1.el8 |
libyang-debugsourceRed Hat:enterprise_linux:8::appstream |
before 0:1.0.184-1.el8 | 0:1.0.184-1.el8 |
python3-libyang-debuginfoRed Hat:enterprise_linux:8::appstream |
before 0:1.0.184-1.el8 | 0:1.0.184-1.el8 |
libyangUbuntu:20.04:LTS |
All versions, plus listed versions 0.16.105-10.16.105-20.16.105-30.16.105-3build1 |
None known |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-03 | aliases | EUVD |
| 2026-11-02 | created | CVE List, GitHub Advisories, NVD, OSV |
References
github.com/CESNET/libyang/compare/v1.0-r2...v1.0-r3
bugzilla.redhat.com/show_bug.cgi?id=1793932
lists.debian.org/debian-lts-announce/2023/09/msg00019.html
nvd.nist.gov/vuln/detail/CVE-2019-20394
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errata.almalinux.org/8/ALEA-2021-1906.html
vulners.com/cve/CVE-2019-20391
security-tracker.debian.org/tracker/CVE-2019-20394
access.redhat.com/errata/RHEA-2021:1906
security.access.redhat.com/data/csaf/v2/advisories/2021/rhea-2021_1906.json
cve.org/CVERecord?id=CVE-2019-20391
ubuntu.com/security/CVE-2019-20394