{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43972", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-05-04T18:23:25.574Z", "datePublished": "2026-06-08T14:12:38.780Z", "dateUpdated": "2026-06-08T14:15:56.058Z"}, "containers": {"cna": {"affected": [{"cpes": ["cpe:2.3:a:ninenines:gun:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["gun_http2"], "packageName": "gun", "packageURL": "pkg:hex/gun", "product": "gun", "programFiles": ["src/gun_http2.erl"], "programRoutines": [{"name": "gun_http2:push_promise_frame/7"}, {"name": "gun_http2:headers_frame/9"}], "repo": "https://github.com/ninenines/gun", "vendor": "ninenines", "versions": [{"lessThan": "2.4.0", "status": "affected", "version": "2.0.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:ninenines:gun:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["gun_http2"], "packageName": "ninenines/gun", "packageURL": "pkg:github/ninenines/gun", "product": "gun", "programFiles": ["src/gun_http2.erl"], "programRoutines": [{"name": "gun_http2:push_promise_frame/7"}, {"name": "gun_http2:headers_frame/9"}], "repo": "https://github.com/ninenines/gun.git", "vendor": "ninenines", "versions": [{"lessThan": "567863ff53802fed21c3b3f25812db7f7ae29676", "status": "affected", "version": "871989eef53663285c165fdfb83a5918ebe00d41", "versionType": "git"}]}], "configurations": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>The vulnerability is exploitable only when gun is configured with a <tt>cookie_store</tt> and connects to an HTTP/2 server with server push enabled.</p>"}], "value": "The vulnerability is exploitable only when gun is configured with a cookie_store and connects to an HTTP/2 server with server push enabled."}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:ninenines:gun:*:*:*:*:*:*:*:*", "versionEndExcluding": "2.4.0", "versionStartIncluding": "2.0.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Lo\u00efc Hoguin"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "Origin Validation Error vulnerability in ninenines gun (<tt>gun_http2</tt> module) allows cross-origin cookie injection via unvalidated HTTP/2 PUSH_PROMISE authority.<p>In <tt>gun_http2:push_promise_frame/7</tt>, the <tt>:authority</tt> pseudo-header from an incoming PUSH_PROMISE frame is stored verbatim into the promised stream record without checking that it matches the connection's origin. When <tt>gun_http2:headers_frame/9</tt> later processes the response headers for the promised stream, it calls <tt>gun_cookies:set_cookie_header/7</tt> with the unvalidated server-supplied authority before any status branching and before user code can act. This violates RFC 7540 \u00a710.6 / RFC 9113 \u00a78.4, which require receivers to treat as a protocol error any push for a resource the server is not authoritative for.</p><p>A malicious or compromised HTTP/2 server can plant cookies scoped to arbitrary third-party domains into the client's shared cookie store. This enables session fixation attacks against those domains and, if the planted cookie overrides a legitimate session token, may result in account takeover. No user interaction beyond making a normal HTTP/2 request to the attacker-controlled server is required.</p><p>This issue affects gun: from 2.0.0 before 2.4.0.</p>"}], "value": "Origin Validation Error vulnerability in ninenines gun (gun_http2 module) allows cross-origin cookie injection via unvalidated HTTP/2 PUSH_PROMISE authority.\n\nIn gun_http2:push_promise_frame/7, the :authority pseudo-header from an incoming PUSH_PROMISE frame is stored verbatim into the promised stream record without checking that it matches the connection's origin. When gun_http2:headers_frame/9 later processes the response headers for the promised stream, it calls gun_cookies:set_cookie_header/7 with the unvalidated server-supplied authority before any status branching and before user code can act. This violates RFC 7540 \u00a710.6 / RFC 9113 \u00a78.4, which require receivers to treat as a protocol error any push for a resource the server is not authoritative for.\n\nA malicious or compromised HTTP/2 server can plant cookies scoped to arbitrary third-party domains into the client's shared cookie store. This enables session fixation attacks against those domains and, if the planted cookie overrides a legitimate session token, may result in account takeover. No user interaction beyond making a normal HTTP/2 request to the attacker-controlled server is required.\n\nThis issue affects gun: from 2.0.0 before 2.4.0."}], "impacts": [{"capecId": "CAPEC-61", "descriptions": [{"lang": "en", "value": "CAPEC-61 Session Fixation"}]}], "metrics": [{"cvssV4_0": {"attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "baseScore": 6.3, "baseSeverity": "MEDIUM", "privilegesRequired": "NONE", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-346", "description": "CWE-346 Origin Validation Error", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-06-08T14:15:56.058Z"}, "references": [{"tags": ["related", "third-party-advisory"], "url": "https://cna.erlef.org/cves/CVE-2026-43972.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43972"}, {"tags": ["patch"], "url": "https://github.com/ninenines/gun/commit/567863ff53802fed21c3b3f25812db7f7ae29676"}], "source": {"discovery": "EXTERNAL"}, "title": "gun HTTP/2 PUSH_PROMISE authority not validated against connection origin allows cross-origin cookie injection", "x_generator": {"engine": "cvelib 1.8.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Origin Validation Error vulnerability in ninenines gun (gun_http2 module) allows cross-origin cookie injection via unvalidated HTTP/2 PUSH_PROMISE authority.\n\nIn gun_http2:push_promise_frame/7, the :authority pseudo-header from an incoming PUSH_PROMISE frame is stored verbatim into the promised stream record without checking that it matches the connection's origin. When gun_http2:headers_frame/9 later processes the response headers for the promised stream, it calls gun_cookies:set_cookie_header/7 with the unvalidated server-supplied authority before any status branching and before user code can act. This violates RFC 7540 \u00a710.6 / RFC 9113 \u00a78.4, which require receivers to treat as a protocol error any push for a resource the server is not authoritative for.\n\nA malicious or compromised HTTP/2 server can plant cookies scoped to arbitrary third-party domains into the client's shared cookie store. This enables session fixation attacks against those domains and, if the planted cookie overrides a legitimate session token, may result in account takeover. No user interaction beyond making a normal HTTP/2 request to the attacker-controlled server is required.\n\nThis issue affects gun: from 2.0.0 before 2.4.0."}], "id": "CVE-2026-43972", "lastModified": "2026-06-08T15:16:46.290", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 6.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-06-08T15:16:46.290", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-43972.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/ninenines/gun/commit/567863ff53802fed21c3b3f25812db7f7ae29676"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-43972"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-346"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

{}

{"created": "2026-06-08T15:30:27.230631+00:00", "updated": "2026-06-08T15:30:27.230643+00:00", "vendors": []}