Vulnerability in github.com/free5gc/udm (CVE-2026-42459)
Summary
Vulnerability in github.com/free5gc/udm (CVE-2026-42459). Confidential information can be exposed externally. Exploitable via supi.
Original description
The description as published by the source.
Summary
The free5GC UDM component fails to validate the supi path parameter in six GET handlers of the nudm-sdm (Subscriber Data Management) service. An unauthenticated attacker can inject control characters into the SUPI parameter, causing UDM to forward a malformed request to UDR and return a 500 Internal Server Error response that exposes internal infrastructure details.
Affected Package
- Ecosystem: Go
- Package:
github.com/free5gc/udm - Affected versions:
<= v1.4.2 - Patched versions: none yet
Details
The following handlers in internal/sbi/api_subscriberdatamanagement.go do not call validator.IsValidSupi() before passing the supi parameter to the processor:
HandleGetSmfSelectData—GET /:supi/smf-select-dataHandleGetSupi—GET /:supiHandleGetTraceData—GET /:supi/trace-dataHandleGetUeContextInSmfData—GET /:supi/ue-context-in-smf-dataHandleGetNssai—GET /:supi/nssaiHandleGetSmData—GET /:supi/sm-data
By contrast, HandleGetAmData in the same file correctly validates the supi parameter:
// HandleGetAmData — correctly validates (not vulnerable)
supi := c.Params.ByName("supi")
if !validator.IsValidSupi(supi) {
c.JSON(http.StatusBadRequest, problemDetail)
return
}
// HandleGetSmfSelectData — missing validation (vulnerable)
supi := c.Params.ByName("supi")
// ← no validator.IsValidSupi(supi) call
s.Processor().GetSmfSelectDataProcedure(c, supi, plmnID, supportedFeatu…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-42459 has been found in github.com/free5gc/udm.
Attackers can target a specific entry point like supi over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "github.com/free5gc/udm CVE-2026-42459" on the vendor's site.
CVE-2026-42459 (github.com/free5gc/udm) — CWE-20 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: supi / HandleGetSmfSelectData / HandleGetSupi / HandleGetTraceData
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-20) exists in github.com/free5gc/udm. Attackers reach the vulnerable code path via supi without authentication.
Check the vendor advisory for the affected versions of github.com/free5gc/udm. Attack surface: supi / HandleGetSmfSelectData / HandleGetSupi / HandleGetTraceData.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/free5gc/udm' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/free5gc/udm' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/free5gc/udmを grep し、稼働しているサービス・バージョンを把握する。 -
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- exploit github.com
- package github.com
- web github.com
- web github.com
- web github.com