CVE-2026-77206

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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."}], "affected": [{"vendor": "The Libreswan Project", "product": "libreswan", "packageName": "libreswan", "collectionURL": "https://github.com/libreswan/libreswan", "repo": "https://github.com/libreswan/libreswan", "versions": [{"version": "4.7", "status": "affected", "lessThanOrEqual": "5.3.2", "versionType": "semver"}, {"version": "5.4", "status": "affected", "lessThanOrEqual": "5.4", "versionType": "semver"}, {"version": "5.3.3", "status": "unaffected", "versionType": "semver"}, {"version": "5.4.1", "status": "unaffected", "versionType": "semver"}], "defaultStatus": "unaffected"}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-476", "description": "CWE-476: Null Pointer Dereference"}]}], "impacts": [{"descriptions": [{"lang": "en", "value": "Denial of service via null pointer dereference in EAP handling code when processing malicious IKE_AUTH packets"}]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}}, {"other": {"type": "vendorSeverity", "content": {"value": "MEDIUM", "description": "Vendor-assessed severity: Medium. Exploitation does not require authentication, but the daemon automatically restarts after the crash, requiring continued exploitation for sustained denial of service."}}}], "workarounds": [{"lang": "en", "value": "Apply the available patch or upgrade to a supported version. No configuration-based workaround is available."}], "solutions": [{"lang": "en", "value": "Upgrade to libreswan 5.3.3 or 5.4.1 or later. Note that EAP was not functional in libreswan 5.3. If you need EAP support, use 5.4.1 or later. Patches are available at https://libreswan.org/security/CVE-2026-77206/"}], "exploits": [{"lang": "en", "value": "No known exploitation in the wild. Exploitation requires sending a malicious IKE_AUTH packet and does not require peer authentication."}], "configurations": [{"lang": "en", "value": "Any server or client that accepts IKEv2 connections is vulnerable. 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Patches are available at https://libreswan.org/security/CVE-2026-77206/"}], "references": [{"url": "https://libreswan.org/security/CVE-2026-77206/CVE-2026-77206.txt", "name": "Libreswan Security Advisory CVE-2026-77206", "tags": ["vendor-advisory"]}, {"url": "https://libreswan.org/security/CVE-2026-77206/", "name": "Libreswan CVE-2026-77206 Patches", "tags": ["patch"]}], "workarounds": [{"lang": "en", "value": "Apply the available patch or upgrade to a supported version. No configuration-based workaround is available."}], "x_generator": {"engine": "cvelib 1.8.0"}, "descriptions": [{"lang": "en", "value": "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. 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{"affected": [{"affectedData": [{"collectionURL": "https://github.com/libreswan/libreswan", "defaultStatus": "unaffected", "packageName": "libreswan", "product": "libreswan", "repo": "https://github.com/libreswan/libreswan", "vendor": "The Libreswan Project", "versions": [{"lessThanOrEqual": "5.3.2", "status": "affected", "version": "4.7", "versionType": "semver"}, {"lessThanOrEqual": "5.4", "status": "affected", "version": "5.4", "versionType": "semver"}, {"status": "unaffected", "version": "5.3.3", "versionType": "semver"}, {"status": "unaffected", "version": "5.4.1", "versionType": "semver"}]}], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-77206", "lastModified": "2026-10-16T19:55:59.740", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-77206", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T15:14:41.074180Z", "version": "2.0.3"}}]}, "published": "2026-10-13T22:18:24.727", "references": [{"source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "url": "https://libreswan.org/security/CVE-2026-77206/"}, {"source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "url": "https://libreswan.org/security/CVE-2026-77206/CVE-2026-77206.txt"}], "sourceIdentifier": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "d42dc95b-23f1-4e06-9076-20753a0fb0df", "type": "Secondary"}]}

{"bugzilla": {"description": "libreswan: IKEv2 pre-authentication Null Pointer deref in EAP code", "id": "2550256", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2550256"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["A null pointer dereference flaw was found in Libreswan's IKEv2 state-machine handling. A remote, unauthenticated attacker can trigger the flaw by sending a malicious IKEv2 IKE_AUTH packet, causing the pluto daemon to crash and restart. Repeated exploitation may result in a denial of service. The vulnerability can be triggered even when EAP is not configured."], "mitigation": {"lang": "en:us", "value": "Red Hat is not aware of a practical temporary workaround that fully mitigates this issue or meets Red Hat Product Security's standards for usability, deployment, applicability, or stability. Customers are advised to apply the relevant security updates when/if they become available."}, "name": "CVE-2026-77206", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:9::fastdatapath", "fix_state": "Affected", "package_name": "libreswan", "product_name": "Fast Datapath for RHEL 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "libreswan", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "libreswan", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "libreswan", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "libreswan", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "libreswan", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "libreswan", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-05T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-77206\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-77206\nhttps://libreswan.org/security/CVE-2026-77206/CVE-2026-77206.txt\nhttps://libreswan.org/security/CVE-2026-77206/libreswan-5.3-CVE-2026-77206.patch\nhttps://libreswan.org/security/CVE-2026-77206/libreswan-5.4-CVE-2026-77206.patch"], "statement": "Red Hat Product Security rates this vulnerability as having a Moderate impact. Exploitation requires Libreswan to be running as an IKEv2 endpoint, a configuration that requires explicit installation and service configuration on a standard Red Hat Enterprise Linux system. A remote, unauthenticated attacker can send a crafted IKEv2 authentication packet to crash the pluto daemon, potentially disrupting VPN connectivity. Repeated exploitation can cause continued denial of service. Remote code execution is not possible.\nThe vulnerability can be triggered even when EAP is not configured.", "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[4.7,5.3.2]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[5.4,5.4]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "5.3.3"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "5.4.1"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "libreswan", "source": "cna", "vendor": "The Libreswan Project"}, "product": "libreswan", "vendor": "libreswan"}], "created": "2026-10-14T17:30:04.780706+00:00", "updated": "2026-10-26T22:49:41.344866+00:00", "vendors": ["libreswan", "libreswan$PRODUCT$libreswan"]}