Back to the CVE list
CVE-2026-77206

IKEv2 pre-authentication Null Pointer Dereference in EAP code

CVSS score

7.5

EPSS probability

%0.5

Risk score

0.0

Published

1 d ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

Libreswan CVE-2026-77206 IKEv2 Null Pointer Dereference Vulnerability

Sources read

1

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

Libreswan's IKEv2 state machine contains a null pointer dereference bug in the EAP handling code for authentication. A malicious IKE_AUTH packet can trigger this bug, leading to a crash and restart of the pluto daemon.

Why does it matter?

An unauthenticated remote attacker can exploit this flaw to trigger a denial of service. While remote code execution is not possible, daemon crashes cause service disruptions.

What should be done?

  • Follow the vendor advisory
  • Apply available patches
  • Update to unaffected versions
Chain of evidence and sources3 verified claims

Libreswan IKEv2 durum makinesi, EAP işleme kodunda bir null pointer dereference açığı barındırır.

S0 · daybreach-canonicalS1 · cvelist

Kötü amaçlı bir IKE_AUTH paketi, kimlik doğrulama gerektirmeden bu açığı tetikleyebilir.

S0 · daybreach-canonicalS1 · cvelist

Açık, pluto daemon'un çökmesine ve sürekli istismar edildiğinde hizmet reddine neden olur.

S0 · daybreach-canonicalS1 · cvelist
Show the technical text from the sources

Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all. The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated. The bug results in a crash and restart of the pluto daemon. No remote code execution is possible. Continued exploitation can cause a denial of service.

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

CWE: CWE-476

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-77206 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1The Libreswan Projectlibreswan View
Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
7.5CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD
7.5CVSS V3_1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

cvelist

Libreswan CVE-2026-77206 Patches

Open source
reference

Libreswan CVE-2026-77206 Patches

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-77206 is associated with the following CWEs:

CWE-476: NULL Pointer Dereference

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-77206 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsGerekmiyor
UserGerekmiyor

Official Sources and Advisories

Libreswan Security Advisory CVE-2026-77206vendor-advisoryLibreswan CVE-2026-77206 Patchespatch

CVSS Vector Radar Chart

7.5 / 10
Attack VectorNetworkComplexityLowPrivilegesNoneUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityHigh

Vulnerability Scoring Details

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone required
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)High

Yama doğrulandı

2 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

TL
The Libreswan Project logo
The Libreswan Project

Weakness Type (CWE & CAPEC)

CWE-476

Similar Vulnerabilities

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free keyDocumentation
curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.daybreach.dev/api/v1/intel/cves/CVE-2026-77206"