CVE-2021-28905
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can...
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
CVE-2021-28905- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-617
- Updated
- 2026-11-02
CVE List No score
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
CVE-2021-28905- Updated
- 2026-11-02
EUVDEUVD-2021-15558 No score
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
EUVD-2021-15558- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-qj7j-m28f-g68x
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can...
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
GHSA-qj7j-m28f-g68x- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-617
- Updated
- 2026-11-02
OSVALPINE-CVE-2021-28905
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
ALPINE-CVE-2021-28905- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-03
OSV
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
CVE-2021-28905- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-28905
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
DEBIAN-CVE-2021-28905- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-28905
In function lys_node_free() in libyang <= v1.0.225, it asserts that the value of node->module can't be NULL. But in some cases, node->module can be null, which triggers a reachable assertion (CWE-617).
- Record
UBUNTU-CVE-2021-28905- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVSUSE-SU-2022:2922-1 No score
Security update for libyang
This update for libyang fixes the following issues:
- CVE-2021-28905: Fixed a reachable assertion which could be exploited by an attacker to cause a denial of service (bsc#1186377).
- Record
SUSE-SU-2022:2922-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libyangAlpine:v3.13 |
before 1.0.184-r1 | 1.0.184-r1 |
libyangAlpine:v3.14 |
before 1.0.215-r1 | 1.0.215-r1 |
libyangDebian:13 |
before 3.4.2+dfsg-2 | 3.4.2+dfsg-2 |
libyangDebian:14 |
before 3.4.2+dfsg-2 | 3.4.2+dfsg-2 |
libyangSUSE:Linux Enterprise Module for Server Applications 15 SP3 |
before 1.0.184-150300.3.3.1 | 1.0.184-150300.3.3.1 |
libyangSUSE:Linux Enterprise Module for Server Applications 15 SP4 |
before 1.0.184-150300.3.3.1 | 1.0.184-150300.3.3.1 |
libyangopenSUSE:Leap 15.3 |
before 1.0.184-150300.3.3.1 | 1.0.184-150300.3.3.1 |
libyangopenSUSE:Leap 15.4 |
before 1.0.184-150300.3.3.1 | 1.0.184-150300.3.3.1 |
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
| Recorded | Changed | Sources |
|---|---|---|
| affected, aliases, references | OSV | |
| 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-2021-28905 is a high vulnerability (CVSS 7.5) in Cesnet Libyang, published May 20, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.42%, the 73rd percentile. Fixed in libyang 1.0.184-r1.