free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-callback route group without inbound OAuth2/bearer-token authorization. A forged or arbitrary bearer token (e.g. Authorization: Bearer not-a-real-token) is enough to reach the SMF-callback handler -- the callback body is parsed and dispatched into NEF business logic instead of being rejected at the auth boundary. Same root cause as the other NEF SBI findings: the route group is mounted without any inbound auth middleware. NEF does not authenticate the producer NF identity before processing callback content; if an attacker can guess or obtain a valid NotifId, this missing auth boundary lets forged callbacks act on real subscription state. The route group is also reachable even when the runtime ServiceList does not declare it (it lists only nnef-pfdmanagement and nnef-oam). This vulnerability is fixed in 4.2.2.
CVE-2026-44320
“—” beside the score: it is equal to NVD's CVSS score.
Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-05-08. NVD baseline CVSS 7.3; sources differ by 0.0.
Also known asEUVD-2026-32578 (ENISA EUVD) · GHSA-wqfh-gq79-j8mf (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
The CVE record names the fixed release — apply it.
- CVSS v3
- 7.3
- EG Score
- 7.3HIGHmedium confidence
- EG Risk
- 48EG Risk 48/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity73% × 45%Impact severity (EG Severity): CVSS 7.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.2% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability100% × 15%CISA's SSVC Automatable value: yes (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.2%
- EPSS %ILE
- 15th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.3): severity, escalated by confirmed exploitation. This CVE's 7.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.3 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).
The CVE record names the fixed release. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
May 27, 2026
Last Modified
October 14, 2026
Advisory Details (3)
Auto-updated Jun 11, 2026NEF nnef-callback route group is unauthenticated; forged callback requests are accepted into the processing path · Advisory · free5gc/free5gc · GitHub
https://github.com/free5gc/free5gc/security/advisories/GHSA-wqfh-gq79-j8mffix(sbi): add inbound OAuth2 middleware to nnef-callback route
Upstream fix in progress (PR #24 · free5gc/nef, state=open)
https://github.com/free5gc/nef/pull/24[Bugs] NEF `nnef-callback` is unauthenticated: forged callback requests are accepted into the processing path · Issue #860 · free5gc/free5gc · GitHub
https://github.com/free5gc/free5gc/issues/860Vendor Advisories for CVE-2026-44320(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(1)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| go | github.com/free5gc/nef | — | ghsa |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| github.com/free5gc/nef | — |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 10× in last 7d / 42× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 100 of 275 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 175 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-28 06:04 UTCEG score recompute
- 2026-10-28 06:04 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-10-25 14:27 UTCEG score recompute
- 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-21 09:13 UTCEG score recompute
- 2026-10-21 09:13 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-18 03:39 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-14 20:28 UTCEG score recompute
- 2026-10-14 20:28 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
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- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-12 16:05 UTCEG score recompute
- 2026-10-11 19:47 UTCEG score recompute
- 2026-10-11 17:02 UTCEG score recompute
- 2026-10-11 14:27 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 30th percentile
- 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-03 16:49 UTCOSV refresh
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 29th percentile
- 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-14 07:37 UTCEG score recompute
- 2026-09-14 07:37 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-13 03:09 UTCOSV refresh
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 14th percentile
- 2026-08-25 05:15 UTCEG score recompute
- 2026-08-25 05:15 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-23 14:59 UTCEG score recompute
- 2026-08-23 14:59 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-21 20:32 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-21 01:29 UTCEG score recompute
- 2026-08-21 01:29 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-20 11:15 UTCEG score recompute
- 2026-08-20 11:15 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-17 09:14 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-16 15:26 UTCEG score recompute
- 2026-08-16 15:26 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-16 02:48 UTCEG score recompute
- 2026-08-16 02:48 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-15 02:55 UTCEG score recompute
- 2026-08-15 02:55 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-14 14:00 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-14 01:25 UTCEG score recompute
- 2026-08-14 01:25 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 15th percentile
- 2026-08-13 05:53 UTCGHSA enrichmentGHSA-wqfh-gq79-j8mf · GitHub severity HIGH · GitHub CVSS 7.3
Related CVEs(same product + same CWE)
Same product
6 shownGo:github.com/free5gc/nef
Frequently asked(5)
What is CVE-2026-44320?
When was the CVE record for CVE-2026-44320 published?
Is CVE-2026-44320 actively exploited?
What is the CVSS score of CVE-2026-44320?
How do I remediate CVE-2026-44320?
Dependency Blast Radius
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