CVE-2026-1521Public exploitNetwork attack vectorHinoki check available

Remote SGWC crash via stale transaction assertion

Published Jan 28, 2026 · Updated Jan 28, 2026

Denial of service in Open5GS SGWC 2.7.0 through 2.7.6 allows remote attackers to crash the SGWC via a delayed S5-C indication. The sgwc_s5c_handle_bearer_resource_failure_indication function asserts that its associated S11 transaction exists after that transaction has timed out and been freed. Exploitation requires control of the S11 and S5-C message sequence and timing; the failed assertion aborts open5gs-sgwcd and interrupts the SGWC service.

CVSS severity5.3
Medium
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in Open5GS SGWC 2.7.0 through 2.7.6 allows remote attackers to crash the SGWC via a delayed S5-C indication. The sgwc_s5c_handle_bearer_resource_failure_indication function asserts that its associated S11 transaction exists after that transaction has timed out and been freed. Exploitation requires control of the S11 and S5-C message sequence and timing; the failed assertion aborts open5gs-sgwcd and interrupts the SGWC service.

The record

CVE
CVE-2026-1521
Published
Jan 28, 2026
Updated
Jan 28, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-404, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 28, 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

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

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
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-404Improper Resource Shutdown or Release
T1499.004Endpoint Denial of Service: Application 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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