CVE-2026-78156Public exploitNetwork attack vector

Authenticated memory over-read via short PLMN identifier

Published Aug 23, 2026 · Updated Aug 23, 2026

Heap buffer over-read in the Open5GS 2.8.0 HSS allows remote authenticated users to trigger an out-of-bounds read via a crafted S6a AIR. The hss_ogs_diam_s6a_air_cb function passes the raw Visited-PLMN-Id buffer to ogs_auc_kasme, which always reads three bytes without first validating the AVP length. The peer must complete Diameter peering and send a zero- or two-byte identifier; public evidence demonstrates the invalid read but not a crash or returned-memory disclosure.

CVSS severity7.4
High
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Heap buffer over-read in the Open5GS 2.8.0 HSS allows remote authenticated users to trigger an out-of-bounds read via a crafted S6a AIR. The hss_ogs_diam_s6a_air_cb function passes the raw Visited-PLMN-Id buffer to ogs_auc_kasme, which always reads three bytes without first validating the AVP length. The peer must complete Diameter peering and send a zero- or two-byte identifier; public evidence demonstrates the invalid read but not a crash or returned-memory disclosure.

The record

CVE
CVE-2026-78156
Published
Aug 23, 2026
Updated
Aug 23, 2026
Vendor
Open5GS
Product
Open5GS
Classifications
CWE-119, CWE-122, T1210
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 23, 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=2.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Open5GS · Open5GSversion=2.8.0

Published CVSS scores

6.5VulDB CNAAV:N/AC:L/Au:S/C:P/I:P/A:P
7.4VulDB CNACVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
2.1VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-122Heap-based Buffer Overflow
T1210Exploitation of Remote Services

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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