CVE-2019-20396
CVE-2019-20396 is a medium-severity vulnerability in Cesnet Libyang with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-119.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v2: 4.3
- EPSS exploit prediction: 2% (77th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-119
- Affected product: Cesnet Libyang
- Published:
- Last modified:
Description
A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lys_parse_path parsing.
Frequently asked questions
- What is CVE-2019-20396?
- A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lys_parse_path parsing.
- How severe is CVE-2019-20396?
- CVE-2019-20396 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2019-20396 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2019-20396?
- CVE-2019-20396 primarily affects Cesnet Libyang. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2019-20396?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2019-20396 published?
- CVE-2019-20396 was published on 2020-01-22 and last updated on 2026-06-17.
References
- https://github.com/CESNET/libyang/commit/a1f17693904ed6fecc8902c747fc50a8f20e6af8
- https://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
- https://github.com/CESNET/libyang/issues/740
- https://lists.debian.org/debian-lts-announce/2023/09/msg00019.html
Affected products (11)
- cpe:2.3:a:cesnet:libyang:0.11:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.11:r2:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.12:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.12:r2:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.13:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.13:r2:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.14:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.15:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.16:r1:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.16:r2:*:*:*:*:*:*
- cpe:2.3:a:cesnet:libyang:0.16:r3:*:*:*:*:*:*
More vulnerabilities in Cesnet Libyang
- CVE-2019-19334 — Critical (CVSS 9.8): In all versions of libyang before 1.0-r5, a stack-based buffer overflow was discovered in the way libyang parses YANG…
- CVE-2019-19333 — Critical (CVSS 9.8): In all versions of libyang before 1.0-r5, a stack-based buffer overflow was discovered in the way libyang parses YANG…
- CVE-2019-20397 — High (CVSS 8.8): A double-free is present in libyang before v1.0-r1 in the function yyparse() when an organization field is not…
- CVE-2019-20394 — High (CVSS 8.8): A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a…
- CVE-2019-20393 — High (CVSS 8.8): A double-free is present in libyang before v1.0-r1 in the function yyparse() when an empty description is used.…
- CVE-2023-26917 — High (CVSS 7.5): libyang from v2.0.164 to v2.1.30 was discovered to contain a NULL pointer dereference via the function…
All CVEs affecting Cesnet Libyang →
Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities
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- CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
- CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
- CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
- CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
- CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.