CVE-2026-78124Network attack vector

Pre-authentication resource exhaustion via unreleased certificate references

Published Sep 11, 2026 · Updated Sep 11, 2026

Memory leak in strongSwan's OpenSSL plugin in 5.0.2 through 6.0.7 allows remote attackers to consume memory via IKEv1 PKCS#7 payloads. CMS_get1_certs() increments references for the certificate stack and its X509 entries, but the enumerator destructor omits sk_X509_pop_free(). The pre-authentication path requires at least two IKEv1 messages and an active OpenSSL plugin; exposure through a pkcs7-first configuration depends on parsing fallback.

CVSS severity8.2
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in strongSwan's OpenSSL plugin in 5.0.2 through 6.0.7 allows remote attackers to consume memory via IKEv1 PKCS#7 payloads. CMS_get1_certs() increments references for the certificate stack and its X509 entries, but the enumerator destructor omits sk_X509_pop_free(). The pre-authentication path requires at least two IKEv1 messages and an active OpenSSL plugin; exposure through a pkcs7-first configuration depends on parsing fallback.

The record

CVE
CVE-2026-78124
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
strongSwan
Product
strongSwan
Classifications
T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=5.0.2 <6.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

strongSwan · strongSwanversion=5.0.2 <6.1.0

Published CVSS scores

5.9SUSECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
8.2SUSECVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.002Service Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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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