CVE-2026-2521Public exploitNetwork attack vector

Remote service crash via unchecked PAA copy

Published Feb 15, 2026 · Updated Feb 15, 2026

Buffer overflow in Open5GS SGW-C 2.7.0 through 2.7.6 allows remote attackers to crash the SGW-C service via a crafted S5-C response. sgwc_s5c_handle_create_session_response copies the declared PAA IE length into sess->paa without checking the destination size. Reachability requires a peer able to answer an active Create Session transaction as the PGW on UDP port 2123; the demonstrated consequence is process termination.

CVSS severity9.8
Critical
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Open5GS SGW-C 2.7.0 through 2.7.6 allows remote attackers to crash the SGW-C service via a crafted S5-C response. sgwc_s5c_handle_create_session_response copies the declared PAA IE length into sess->paa without checking the destination size. Reachability requires a peer able to answer an active Create Session transaction as the PGW on UDP port 2123; the demonstrated consequence is process termination.

The record

CVE
CVE-2026-2521
Published
Feb 15, 2026
Updated
Feb 15, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-119, CAPEC-100, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 15, 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

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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
5.0VulDBAV:N/AC:L/Au:N/C:N/I:N/A: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-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CAPEC-100Overflow Buffers
T1498Network 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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