CVE-2026-8226Public exploitNetwork attack vector

PCF restart via malformed flow description assertion

Published May 10, 2026 · Updated May 10, 2026

Denial of service in Open5GS 2.7.0 through 2.7.7 allows remote attackers to restart the PCF through a malformed flow description. flow_rx_to_gx() searches text following "permit in" for a required "from" token and asserts when that token is absent. An unauthenticated POST or PATCH to the Npcf_PolicyAuthorization app-session routes triggers the assertion and restarts only the PCF process.

CVSS severity7.5
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Open5GS 2.7.0 through 2.7.7 allows remote attackers to restart the PCF through a malformed flow description. flow_rx_to_gx() searches text following "permit in" for a required "from" token and asserts when that token is absent. An unauthenticated POST or PATCH to the Npcf_PolicyAuthorization app-session routes triggers the assertion and restarts only the PCF process.

The record

CVE
CVE-2026-8226
Published
May 10, 2026
Updated
May 10, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-404, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 10, 2026CVE publishedPublication date reported by the CVE source.
  2. May 10, 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

7.5NVDCVSS: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
5.0VulDBAV:N/AC:L/Au:N/C:N/I:N/A:P
5.5VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

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-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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