CVE-2026-8187Public exploitNetwork attack vector

User-plane service degradation via unbounded GTP-U processing

Published May 9, 2026 · Updated May 9, 2026

Resource consumption in Open5GS UPF 2.7.0 through 2.7.7 allows remote attackers to degrade user-plane service via GTP-U traffic. The _gtpv1_u_recv_cb hot path performs synchronous logging, packet hexdumps, and protocol responses for each Echo Request or unknown TEID without rate limiting. Exploitation requires sustained high-rate access to the UPF GTP-U endpoint and increases latency and packet loss; the upstream project disputes that the behavior is a bug.

CVSS severity6.9
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource consumption in Open5GS UPF 2.7.0 through 2.7.7 allows remote attackers to degrade user-plane service via GTP-U traffic. The _gtpv1_u_recv_cb hot path performs synchronous logging, packet hexdumps, and protocol responses for each Echo Request or unknown TEID without rate limiting. Exploitation requires sustained high-rate access to the UPF GTP-U endpoint and increases latency and packet loss; the upstream project disputes that the behavior is a bug.

The record

CVE
CVE-2026-8187
Published
May 9, 2026
Updated
May 9, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-400, CWE-404, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 9, 2026CVE publishedPublication date reported by the CVE source.
  2. May 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 privilegesunauthenticated

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

5.0VulDBAV:N/AC:L/Au:N/C:N/I:N/A:P
6.9VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
7.5NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-404Improper Resource Shutdown or Release
T1499.004Application or System Exploitation

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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