CVE-2026-55068: free5GC: NRF nnrf-nfm lacks NF Profile input validation — enables NF Registration Poisoning with arbitrary service endpoints
Noroxi assessment
Priority: Monitor (action score 37/100)
- 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: 0.59% (FIRST EPSS).
- 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.
- Fixed version: free5gc free5gc 4.2.3.
Low priority for now. Upgrade to free5gc free5gc 4.2.3 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 implementation of the 5G core network. In 4.2.2 and earlier, the NRF RegisterNFInstance handler at PUT /nnrf-nfm/v1/nf-instances/{nfInstanceID} accepts NF Profiles without enforcing UUID format, nfStatus enum values, heartBeatTimer ranges, mandatory profile fields, or nfServices.ipEndPoints address constraints. The invalid profiles are persisted in the MongoDB NfProfile collection and returned by NFDiscover, allowing an attacker with SBI access to advertise attacker-controlled network-function endpoints and redirect control-plane signaling. This can expose credentials and signaling, alter service discovery integrity, and deny service across network functions that trust the NRF. This issue is fixed in version 4.2.3.
- Published
- Aug 28, 2026
- Updated
- Sep 8, 2026
- EPSS
- 0.5% · 48th percentile
- CWE
- CWE-20
Report tools
Action score
37
Monitor
Low priority for now.
- CVSS
- 37 / 40 · 9.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 9.3
- 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:H/VI:H/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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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.
We use this product, ask for helpAffected 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.
—
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 free5gc
- < 4.2.3affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Go | github.com/free5gc/free5gc | before 4.2.2 | 4.2.2 |
| Go | github.com/free5gc/free5gc | before 4.2.2+incompatible | 4.2.2+incompatible |
| openSUSE:Leap 16.0 | govulncheck-vulndb | before 0.0.20260902T191204-160000.1.1 | 0.0.20260902T191204-160000.1.1 |
| SUSE:Linux Enterprise Server 16.0 | govulncheck-vulndb | before 0.0.20260902T191204-160000.1.1 | 0.0.20260902T191204-160000.1.1 |
Same product
free5gc: all recordsOther 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 subscriptions40Plan
- CVE-2026-44329free5GC: SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers40Plan
- CVE-2026-44327free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler40Plan
Published before and after this one in the same product
- ← EarlierCVE-2026-44328May 27, 2026 · free5GC: SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating32Monitor
- ← EarlierCVE-2026-53551Jul 31, 2026 · free5GC AUSF: null byte injection in supiOrSuci causes HTTP 500 internal service failure27Monitor
- Later →CVE-2026-55785Aug 28, 2026 · free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA14Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| free5gc free5gc | 4.2.3 · description | Vendor (CNA) |
| Go:github.com/free5gc/free5gc | 4.2.2 | Package registry (OSV) |
| Go:github.com/free5gc/free5gc | 4.2.2+incompatible | Package registry (OSV) |
| opensuse:govulncheck-vulndb | 0.0.20260902T191204-160000.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
| suse:govulncheck-vulndb | 0.0.20260902T191204-160000.1.1 · SUSE:Linux Enterprise Server 16.0 | Package 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.
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 researchersFinders, 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-2026-4245993 days apartfree5GC: Improper Input Validation and Generation of Error Message Containing Sensitive Information in github.com/free5gc/udm30Monitor
- CVE-2026-4431993 days apartfree5GC: NEF crashes via logger.Fatal on PFD notification delivery failure (attacker-controlled notifyUri)30Monitor
- CVE-2026-4432593 days apartfree5GC: NRF POST /oauth2/token structured-form parser type-confusion panic family (Reflect.Set on incompatible types)30Monitor
- CVE-2025-70123196 days apartAn improper input validation and protocol compliance vulnerability in free5GC v4.0.1 allows remote attackers to cause a denial of service.30Monitor
- CVE-2025-65561253 days apartAn issue was discovered in function LocalNode.Sess in free5GC 4.1.0 allowing attackers to cause a denial of service or other unspecified imp30Monitor
- CVE-2026-4778018 days apartfree5GC: UDR Improper ueId validation in free5GC EE subscription handlers allows arbitrary identifier persistence27Monitor
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-20 · Improper Input ValidationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (6 more)Show less
- github.com/free5gc/free5gc/releases/tag/v4.2.3
- github.com/free5gc/free5gc/security/advisories/GHSA-x8mj-6p3q-g5pp
- github.com/free5gc/nrf/commit/bda0cf75be5556bb4c758c8b34710f3fe6bbe3ea
- github.com/free5gc/nrf/commit/fcd3cfaa27cc4dc17172ee0c4c3e0a3a696297c6
- github.com/free5gc/nrf/pull/90
- github.com/free5gc/nrf/releases/tag/v1.4.5
Vendor advisories and official records. Exploit/PoC links are deliberately left out.