VulnerabilityPublished 26 Oct 2026

CVE-2026-94453: libreswan security update

Affects libreswanSource GCVE Database

Mentioned vulnerabilities

Authoritative record:CVE-2026-94453· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 4.15-11.el9_8 soon.

Data as of 26 Oct 2026, 23:30 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

Patch: Available – fixed in 4.15-11.el9_8

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 13 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

almalinux-9

What to do

Upgrade the AlmaLinux libreswan package to 4.15-11.el9_8.

Patches and advisories

access.redhat.com/errata/RHSA-2026:89748 (opens in a new tab)

Affected software

Product	Affected	Fixed in
AlmaLinux 9libreswan	Affected <4.15-11.el9_8	Fixed in 4.15-11.el9_8

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A security update fixing these vulnerabilities is available in Libreswan version 4.15-11.el9_8. Users should apply the update provided by Red Hat for their respective Red Hat Enterprise Linux 9.8 systems. No additional mitigation actions are indicated by the vendor advisory.

Description

Libreswan, an IPsec and IKE implementation for Linux, has multiple security vulnerabilities including a Use-After-Free bug in IKEv2 when using IKE-over-TCP (CVE-2026-94453). These issues affect versions prior to 4.15-11.el9_8. The vulnerabilities could impact the secure tunneling capabilities of VPNs relying on Libreswan. A security update fixing these issues is available from Red Hat.

Impact

The Use-After-Free vulnerability in IKEv2 could potentially lead to denial of service or other memory corruption consequences during VPN tunnel establishment over TCP. The null pointer dereferences may cause crashes or denial of service. These vulnerabilities impact the reliability and security of VPN connections using affected Libreswan versions. No known exploits in the wild have been reported.

References

Community reviews

Loading reviews…