CVE-2026-2521
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 · uneditedA weakness has been identified in Open5GS up to 2.7.6. This issue affects the function sgwc_s5c_handle_create_session_response of the component SGW-C. Executing a manipulation can lead to memory corruption. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
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 memory corruption vulnerability exists in Open5GS SGW-C component's sgwc_s5c_handle_create_session_response function up to version 2.7.6. The flaw allows remote attackers to corrupt memory via manipulated session response messages on the S5/S8 control plane interface, leading to potential code execution or service disruption.
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<= 2.7.6CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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.
-
Identify if Open5GS is installedRun 'open5gs --version' or check installed packages with your package manager (dpkg -l | grep open5gs, rpm -qa | grep open5gs, or similar)Affected if Open5GS is present and version is 2.7.6 or lower
-
Confirm SGW-C component is deployedCheck running processes for sgwc (e.g., 'ps aux | grep sgwc' or systemctl status open5gs-sgwc)Affected if The SGW-C service is running as part of your Open5GS deployment
-
Verify version against vulnerable rangeCompare your installed Open5GS version to the affected range: any version <= 2.7.6 is vulnerableAffected if Installed version is 2.7.6 or lower
-
Check network exposure of S5/S8 control planeReview firewall rules and network configuration to determine if the SGW-C S5/S8 control plane interface is accessible from untrusted networks (e.g., netstat -tlnp | grep sgwc, or inspect firewall/iptables rules)Affected if SGW-C interface is exposed to external or untrusted networks without proper access controls
-
Inspect for indicators of compromiseReview SGW-C logs for anomalies (e.g., unusual session creation responses, memory allocation failures, or crashes in /var/log/open5gs/sgwc.log or equivalent log location)Affected if Logs show unexpected session response handling, memory corruption errors, or unexplained service restarts
You are affected if Open5GS version 2.7.6 or lower is deployed with the SGW-C component running and its S5/S8 interface is network-accessible.
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.
From vendor dataApply vendor patch when available; until then, restrict network access to SGW-C interfaces and monitor for indicators of compromise. Consider network segmentation of 5G control plane infrastructure.
- Consultation6.0 h
- Implementation8.0 h
- Testing12.0 h
- Review / QA6.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,832.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-2521 — 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-2026-2521 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