Is CVE-2026-78131 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-78131 being exploited in the wild.

How severe is CVE-2026-78131?

Low severity, with a CVSS score of 3.7, published 11 September 2026.

Which products and versions are affected?

strongSwan 4.2.0 through 6.0.7.

Is there a fix for CVE-2026-78131?

A patch was published on 2026-09-07: strongSwan 6.1.0 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-78131 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-78131?

Check whether you run strongSwan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-78131: strongSwan x509 plugin memory leak in attribute certificate parsing

CVE-2026-78131 · Severity: low · CVSS 3.7 · Published 2026-09-11

strongSwan is an IPsec VPN implementation widely used to establish secure network connections. A memory leak flaw in the x509 certificate plugin can cause progressive memory exhaustion when processing specially crafted attribute certificates received during VPN connection setup, potentially leading to service denial through resource depletion. This affects VPN gateways and clients that receive untrusted attribute certificates from peers.

Technologies: strongSwan. Vendors: strongSwan.

Quick answers

Is CVE-2026-78131 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-78131 being exploited in the wild.
How severe is CVE-2026-78131?: Low severity, with a CVSS score of 3.7, published 11 September 2026.
Which products and versions are affected?: strongSwan 4.2.0 through 6.0.7.
Is there a fix for CVE-2026-78131?: A patch was published on 2026-09-07: strongSwan 6.1.0 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-78131 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-78131?: Check whether you run strongSwan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A memory management flaw exists in the x509 plugin's parse_directoryName() and extension parsing functions. When processing GeneralName entries in attribute certificate Holder/Issuer fields (RFC 5755), the parser enumerates identification_t objects but only retains the first one, leaving subsequent entries unreleased. Similarly, multiple AuthorityKeyIdentifier extensions are not properly freed before reassignment. An attacker can send IKEv2 CERT payloads (encoding type 10) containing attribute certificates with many such entries, causing progressive memory leaks. This requires no authentication and affects any strongSwan installation with the x509 plugin loaded (default configuration). Remote code execution is not possible; impact is limited to denial of service via memory exhaustion.

Affected products

strongSwan strongSwan 4.2.0 through 6.0.7

Timeline

2026-09-07: disclosed
2026-09-07: patched: strongSwan 6.1.0 released with fix

References

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