---
id: "CVE-2026-106808"
kind: "vulnerability"
aliases: ["CVE-2026-106808"]
title: "OpenAirInterface 5G core: oversized hex input crashes UDM via stack overflow"
severity: "high"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "oai-cn5g-udm", "fixed": [], "affected": "2.2.1", "ecosystem": "vendor"}]
ecosystems: []
tags: ["5g-core", "oai-cn5g", "openairinterface", "other", "self-hosted", "udm"]
not_affected_if: ["other-versions", "sbi-isolated"]
published_at: "2026-11-02T18:18:34+00:00"
first_seen_at: "2026-11-02T18:24:24+00:00"
updated_at: "2026-11-02T18:25:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106808", "first_seen_at": "2026-11-02T18:24:24+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-02T18:25:33+00:00"}]
---

# OpenAirInterface 5G core: oversized hex input crashes UDM via stack overflow

OpenAirInterface Core Network v2.2.1 has a stack buffer overflow in the UDM's Nudm_UEAU Generate Authentication Data endpoint, where attacker-supplied rand and auts hex strings are copied into fixed-size stack buffers without a size check. An attacker can overwrite stack memory, corrupt the stack canary, and terminate the UDM process.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:oai-cn5g-udm affected 2.2.1 fixed ?

## How to check

- Check whether you run OpenAirInterface CN5G UDM v2.2.1 (container image tag or git tag v2.2.1 of oai-cn5g-udm).
- Check whether the UDM SBI (Nudm_UEAU, Generate Authentication Data) is reachable from anything other than your trusted network functions. Exploitation needs SBI access and a valid SUPI.
- Also check any other version built from the same UDM code; NVD names only v2.2.1.

## Timeline

- 2026-11-02T18:24:24+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-106808
- 2026-11-02T18:25:33+00:00 analyst — Only NVD found (page has no body text). No vendor advisory or fix located; OAI v2.2.1 tag (Apr 2026) is the affected version per NVD, no later release/patch confirmed. Nothing verified. Settle by checking github.com/openairinterface oai-cn5g-udm for a commit bounding hex_str_to_uint8 input.

## Documents

- [describes] NVD CVE-2026-106808 https://nvd.nist.gov/vuln/detail/CVE-2026-106808

## From the sources

OpenAirInterface Core Network v2.2.1 has a stack-based buffer overflow vulnerability in the OAI CN5G UDM Nudm_UEAU Generate Authentication Data endpoint. The UDM passes attacker-controlled resynchronizationInfo.rand and auts values to conv::hex_str_to_uint8(), which converts arbitrary-length hex strings into fixed-size stack buffers without validating the destination size. An unauthenticated attacker with access to the SBI interface and a valid SUPI can submit an oversized value to overwrite adjacent stack memory, corrupt the stack canary, and terminate the UDM process.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_