CVE-2025-15539Public exploitNetwork attack vectorHinoki check available

SGW-C crash via stale-bearer assertion

Published Jan 18, 2026 · Updated Jan 18, 2026

Denial of service in Open5GS 2.7.0 through 2.7.6 allows remote attackers to crash SGW-C via a delayed S11 DDN Ack. The sgwc_s11_handle_downlink_data_notification_ack function looks up a bearer retained by the transaction after session teardown and fatally asserts when that bearer or its session no longer exists. Exploitation requires an S11 session lifecycle followed by a late GTPv2-C acknowledgment, and the resulting assertion terminates the SGW-C process.

CVSS severity5.3
Medium
EPSS probability0.75%
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 2.7.0 through 2.7.6 allows remote attackers to crash SGW-C via a delayed S11 DDN Ack. The sgwc_s11_handle_downlink_data_notification_ack function looks up a bearer retained by the transaction after session teardown and fatally asserts when that bearer or its session no longer exists. Exploitation requires an S11 session lifecycle followed by a late GTPv2-C acknowledgment, and the resulting assertion terminates the SGW-C process.

The record

CVE
CVE-2025-15539
Published
Jan 18, 2026
Updated
Jan 18, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-404, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 18, 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

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

5.0VulDBAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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
T1499Endpoint Denial of Service

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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