CVE-2023-36998

Adjacent MME crash via oversized emergency number list

Published Jan 22, 2025 · Updated Jul 5, 2026

Stack-based buffer overflow in NextEPC MME 1.0.1 and earlier allows remote attackers to crash the MME via a crafted NAS message. The nas_decode_emergency_number_list function trusts the encoded length and uses memcpy to copy the oversized field into a fixed destination, overwriting the stack. Reachability requires a cellphone connection to a base station managed by the MME, but no LTE-core authentication; repeated messages interrupt cellular service.

CVSS severity8.9
High
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in NextEPC MME 1.0.1 and earlier allows remote attackers to crash the MME via a crafted NAS message. The nas_decode_emergency_number_list function trusts the encoded length and uses memcpy to copy the oversized field into a fixed destination, overwriting the stack. Reachability requires a cellphone connection to a base station managed by the MME, but no LTE-core authentication; repeated messages interrupt cellular service.

The record

CVE
CVE-2023-36998
Published
Jan 22, 2025
Updated
Jul 5, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-121, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.9CISA-ADPCVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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