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NVD / CVE Program· CNA GitHub_M

CVE-2026-33063: free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion

Noroxi assessment

Priority: Monitor (action score 34/100)

  • 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: 0.67% (FIRST EPSS); higher than 52.1% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: github.com/free5gc/ausf (Go) 1.4.2.

Low priority for now. Upgrade to github.com/free5gc/ausf (Go) 1.4.2 or later.

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

free5GC is an open source 5G core network. free5GC AUSF prior to version 1.4.2 has is an Improper Null Check vulnerability leading to Denial of Service. All deployments of free5GC v4.0.1 using the AUSF UE authentication service (`/nausf-auth/v1/ue-authentications` endpoint) are affected. A remote attacker can cause the AUSF service to panic and crash by sending a crafted UE authentication request that triggers a nil interface conversion in the `GetSupiFromSuciSupiMap` function. This results in complete denial of service for the AUSF authentication service. The `GetSupiFromSuciSupiMap` function attempts to perform an interface conversion from `interface{}` to `*context.SuciSupiMap` without checking if the underlying value is nil. When `SuciSupiMap` is nil, the code panics with "interface conversion: interface {} is nil, not *context.SuciSupiMap". free5GC AUSF version 1.4.2 patches the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the AUSF API to trusted sources only.

HighCVSS 8.7 · v4.0—No exploit Fix available
Published
Mar 19, 2026
Updated
Jun 17, 2026
EPSS
0.6% · 52th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.7
NVD has not scored this yet; the score shown is the CNA’s.

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

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
  • A fix has been released

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

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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
free5gcfree5gc

Affected versions

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

  • free5gc free5gcbefore 1.4.2

Versions reported by the vendor

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

  • free5gc ausf

    • < 1.4.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Gogithub.com/free5gc/ausfbefore 1.4.21.4.2

Same product

free5gc: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-44330free5GC: NEF nnef-pfdmanagement API is unauthenticated; forged bearer tokens can read PFD data and create/delete PFD subscriptions
    40Plan
  • CVE-2026-44329free5GC: SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers
    40Plan
  • CVE-2026-44327free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-32937Mar 19, 2026 · free5GC CHF has Out-of-Bounds Slice Access that Leads to DoS
    28Monitor
  • ← EarlierCVE-2026-33062Mar 19, 2026 · free5GC NRF Discovery EncodeGroupId Function Panics on Malformed group-id-list Parameter
    34Monitor
  • Later →CVE-2026-30653Mar 24, 2026 · An issue in Free5GC v.4.2.0 and before allows a remote attacker to cause a denial of service via the function HandleAuthenticationFailure of
    30Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Go:github.com/free5gc/ausf1.4.2Package registry (OSV)

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.

No history yet (it accumulates with the daily EPSS job).

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.

No credits in the CNA record.

Variant candidates

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

  • CVE-2026-4431669 days apartfree5GC: PCF npcf-smpolicycontrol POST /sm-policies panics on downstream UDR/OpenAPI 404 via nil pointer dereference
    30Monitor
  • CVE-2026-4432269 days apartfree5GC: NEF 3gpp-pfd-management PATCH applications/{appId} panics on UDR access failure due to nil ProblemDetails dereference
    30Monitor
  • CVE-2026-4431769 days apartfree5GC: PCF npcf-policyauthorization POST /app-sessions panics on suppFeat=1 with missing AfRoutReq via nil pointer dereference
    26Monitor
  • CVE-2026-4432369 days apartfree5GC: UDR nudr-dr DELETE amf-subscriptions panics on missing subsId when UE state exists (nil pointer dereference)
    26Monitor

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.
  • No account or password is required.
  • 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
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

  1. Fix✗ → ✓

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References

Show all references (3 more)

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

All records