CVE-2026-33064: free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference
Vulnerability summary
CVE-2026-33064 is a high (CVSS 8.7) vulnerability in free5gc. EPSS estimates a 0.81% chance of exploitation in the next 30 days, higher than 56.4% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 20-03-2026PublishedVulnerability first disclosed.
- 20-03-2026Last modifiedVulnerability information updated.
Description
Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. Versions prior to 1.4.2 are vulnerable to procedure panic caused by Nil Pointer Dereference in the /sdm-subscriptions endpoint. A remote attacker can cause the UDM service to panic and crash by sending a crafted POST request to the /sdm-subscriptions endpoint with a malformed URL path containing path traversal sequences (../) and a large JSON payload. The DataChangeNotificationProcedure function in notifier.go attempts to access a nil pointer without proper validation, causing a complete service crash with "runtime error: invalid memory address or nil pointer dereference". Exploitation would result in UDM functionality disruption until recovery by restart. This issue has been fixed in version 1.4.2.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- OSV · GoEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- NVDNIST8.7HighCVSS: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
EPSS trend
Probability
0.81%
Chance of exploitation in the next 30 days
Percentile
56%
Versus all other CVEs
30-day change
Increase +0.32 pp
From 0.49% on 22-09-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
1 foundFree5Gc
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Ubuntu157 products
- linuxAll versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Github.com/free5gc1 product
- udm< 1.4.2
3 vendors · 160 products
References
8 links- github.com/free5gc/free5gc/security/advisories/GHSA-7g27-v5wj-jr75X Refsource CONFIRMREPORTWEBAdvisoryPatchVendor Advisory
- github.com/free5gc/free5gc/issues/781X Refsource MISCREPORTWEBExploitIssue TrackingPatchVendor Advisory
- github.com/free5gc/udm/commit/65d7070f4bfd016864cbbaefbd506bbc85d2fa92X Refsource MISCREPORTWEBFIXPatch
- github.com/free5gc/udmPACKAGE