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NVD / CVE Program· CNA VulDB

CVE-2026-8743: Open5GS AMF/MME context.c ran_ue_find_by_amf_ue_ngap_id improper authorization

Noroxi assessment

Priority: Monitor (action score 8/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • No fixed version is recorded, but the references include a patch (commit or PR) link.
  • Severity is disputed: the assigning authority (CNA) scores it 5.3, NVD 2.1.

Low priority for now. See the fix and affected versions sections below.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability was found in Open5GS up to 2.7.6. This impacts the function ran_ue_find_by_amf_ue_ngap_id of the file src/amf/context.c of the component AMF/MME. Performing a manipulation results in improper authorization. It is possible to initiate the attack remotely. The exploit has been made public and could be used. The patch is named 5746b8576cfceec18ed87eb7d8cf11b1fb4cd8b1. It is suggested to install a patch to address this issue.

LowCVSS 2.1 · v4.0—No exploit No fix recorded
Published
May 17, 2026
Updated
Oct 21, 2026
EPSS
0.2% · 19th percentile

Report tools

JSON

Action score

8

Monitor

Low priority for now.

CVSS
8 / 40 · 2.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · VulDB
5.3
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-8743

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
open5gsopen5gs

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • open5gs open5gsup to 2.7.6 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (VulDB). Independent of NVD's CPE analysis and usually ahead of it.

  • n/a Open5GS

    • 2.7.0, 2.7.1, 2.7.2, 2.7.3, 2.7.4, 2.7.5, 2.7.6affected

Same product

open5gs: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-28122A request-validation issue was discovered in Open5GS 2.1.3 through 2.2.x before 2.2.1.
    40Plan
  • CVE-2024-40130open5gs v2.6.4 is vulnerable to Buffer Overflow.
    39Monitor
  • CVE-2024-40129Open5GS v2.6.4 is vulnerable to Buffer Overflow.
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-8745May 17, 2026 · Open5GS AUSF nausf-handler.c ogs_timer_add denial of service
    8Monitor
  • ← EarlierCVE-2026-8746May 17, 2026 · Open5GS NRF nghttp2-server.c discover_handler use after free
    8Monitor
  • Later →CVE-2026-15720Jul 14, 2026 · Pre-auth heap out-of-bounds read in the AMF NAS 5GS mobile-identity handler
    34Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
X

Weakness class (CWE)

CWE-266 · Incorrect Privilege Assignment

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records