CVE-2026-8731Public exploitNetwork attack vector

NRF service crash via SBI client exhaustion

Published May 17, 2026 · Updated May 17, 2026

Resource exhaustion in Open5GS NRF 2.7.0 through 2.7.7 allows remote authenticated users to crash the NRF service via subscription requests. Repeated valid POST requests with distinct nfStatusNotificationUri hosts allocate new SBI clients until the fixed 64-entry client_pool is exhausted, after which an unchecked NULL return reaches ogs_assert(client). Access to the NRF subscription endpoint is required; the 65th distinct notification host terminates the NRF process, interrupting that network function until restart.

CVSS severity6.5
Medium
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Open5GS NRF 2.7.0 through 2.7.7 allows remote authenticated users to crash the NRF service via subscription requests. Repeated valid POST requests with distinct nfStatusNotificationUri hosts allocate new SBI clients until the fixed 64-entry client_pool is exhausted, after which an unchecked NULL return reaches ogs_assert(client). Access to the NRF subscription endpoint is required; the 65th distinct notification host terminates the NRF process, interrupting that network function until restart.

The record

CVE
CVE-2026-8731
Published
May 17, 2026
Updated
May 17, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-404, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 17, 2026CVE publishedPublication date reported by the CVE source.
  2. May 17, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.7.0
  2. Affected versionversion=2.7.1
  3. Affected versionversion=2.7.2
  4. Affected versionversion=2.7.3
  5. Affected versionversion=2.7.4
  6. Affected versionversion=2.7.5
  7. Affected versionversion=2.7.6
  8. Affected versionversion=2.7.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Open5GS · Open5GSversion=2.7.0; version=2.7.1; version=2.7.2; version=2.7.3; version=2.7.4; version=2.7.5; version=2.7.6; version=2.7.7

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
T1499.003Application Exhaustion Flood

Public exploit references

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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