FedoraOperating system · Fedoraproject
CVE-2023-26916
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedlibyang from v2.0.164 to v2.1.30 was discovered to contain a NULL pointer dereference via the function lys_parse_mem at lys_parse_mem.c.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA NULL pointer dereference vulnerability exists in libyang versions v2.0.164 through v2.1.30 in the lys_parse_mem function at lys_parse_mem.c. The vulnerability occurs when the function attempts to dereference a NULL pointer during YANG model parsing, potentially causing a denial of service or undefined behavior.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FedoraOperating system
= 36= 37>= 2.0.164, <= 2.1.30CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Check installed libyang versionRun 'rpm -qa | grep libyang' (Fedora) or check with your package manager: 'dpkg -l | grep libyang' (Debian-based) or compile version check from application linking the libraryAffected if Version is between v2.0.164 and v2.1.30 inclusive
-
Identify libyang library fileLocate the libyang shared library: 'find /usr -name "libyang*" -type f' or check application dependency with 'ldd <application_binary>'Affected if The library file exists and links to a vulnerable version from the affected range
-
Verify lys_parse_mem is in useIdentify applications or tools that perform YANG model parsing - these typically include tools like sysrepo,Confd, NETCONF clients/servers, or any custom code calling lys_parse_memAffected if The lys_parse_mem function is called to parse YANG models in your environment
You are affected if libyang version v2.0.164 through v2.1.30 is installed and any application uses the lys_parse_mem function to parse YANG data.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade libyang to a version beyond v2.1.30 where the NULL pointer dereference in lys_parse_mem has been fixed, or apply any available vendor patches for affected versions.
libyang >= 2.1.48 (or latest stable release beyond 2.1.30)
- 1. Identify the current libyang version installed on the system using package manager or binary version check.
- 2. For Fedora systems, run 'dnf check-update' to check for available package updates.
- 3. Upgrade libyang to a version newer than 2.1.30 (e.g., 2.1.48 or later) using 'dnf update libyang' or equivalent package manager command.
- 4. Verify the upgrade was successful by checking the new libyang version.
- 5. Rebuild or restart any applications that link against libyang to ensure they use the updated library.
- 6. Test the functionality that uses lys_parse_mem to confirm the NULL pointer dereference is resolved.
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-26916 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-26916 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data