{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-78661", "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "state": "PUBLISHED", "assignerShortName": "Go", "dateReserved": "2026-08-24T23:36:15.738Z", "datePublished": "2026-10-27T21:38:56.517Z", "dateUpdated": "2026-10-27T21:38:56.517Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc", "shortName": "Go", "dateUpdated": "2026-10-27T21:38:56.517Z"}, "title": "Avoid quadratic complexity when coalescing text nodes in html in golang.org/x/net", "descriptions": [{"lang": "en", "value": "When coalescing adjacent text nodes in addText and fosterParent, appending to an existing TextNode's Data via string concatenation (n.Data += text) reallocated and copied the accumulated string on every token. Inputs containing many short text runs separated by ignored end tags (such as \"a</x>\") caused O(n^2) allocations and byte copies. Accumulate coalesced text in per-node byte slices during parsing and materialize Data strings once at the end of parse."}], "affected": [{"vendor": "golang.org/x/net", "product": "golang.org/x/net/html", "collectionURL": "https://pkg.go.dev", "packageName": "golang.org/x/net/html", "versions": [{"version": "0", "lessThan": "0.62.0", "status": "affected", "versionType": "semver"}], "programRoutines": [{"name": "parser.addText"}, {"name": "parser.fosterParent"}, {"name": "parser.parse"}, {"name": "Parse"}, {"name": "ParseFragment"}, {"name": "ParseFragmentWithOptions"}, {"name": "ParseWithOptions"}], "defaultStatus": "unaffected"}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-407: Inefficient Algorithmic Complexity"}]}], "references": [{"url": "https://go.dev/cl/849365"}, {"url": "https://go.dev/issue/82224"}, {"url": "https://groups.google.com/g/golang-announce/c/sqrs2vTx_Xs"}, {"url": "https://pkg.go.dev/vuln/GO-2026-6860"}], "credits": [{"lang": "en", "value": "Markus Magnuson"}]}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://pkg.go.dev", "defaultStatus": "unaffected", "packageName": "golang.org/x/net/html", "product": "golang.org/x/net/html", "programRoutines": [{"name": "parser.addText"}, {"name": "parser.fosterParent"}, {"name": "parser.parse"}, {"name": "Parse"}, {"name": "ParseFragment"}, {"name": "ParseFragmentWithOptions"}, {"name": "ParseWithOptions"}], "vendor": "golang.org/x/net", "versions": [{"lessThan": "0.62.0", "status": "affected", "version": "0", "versionType": "semver"}]}], "source": "security@golang.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "When coalescing adjacent text nodes in addText and fosterParent, appending to an existing TextNode's Data via string concatenation (n.Data += text) reallocated and copied the accumulated string on every token. Inputs containing many short text runs separated by ignored end tags (such as \"a</x>\") caused O(n^2) allocations and byte copies. Accumulate coalesced text in per-node byte slices during parsing and materialize Data strings once at the end of parse."}], "id": "CVE-2026-78661", "lastModified": "2026-10-28T15:24:56.033", "metrics": {}, "published": "2026-10-27T22:18:05.930", "references": [{"source": "security@golang.org", "url": "https://go.dev/cl/849365"}, {"source": "security@golang.org", "url": "https://go.dev/issue/82224"}, {"source": "security@golang.org", "url": "https://groups.google.com/g/golang-announce/c/sqrs2vTx_Xs"}, {"source": "security@golang.org", "url": "https://pkg.go.dev/vuln/GO-2026-6860"}], "sourceIdentifier": "security@golang.org", "vulnStatus": "Deferred"}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,0.62.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "manual", "scores": [{"score": 100.0, "source": "manual"}]}, "original": {"product": "golang.org/x/net/html", "source": "cna", "vendor": "golang.org/x/net"}, "product": "net", "vendor": "golang"}], "created": "2026-10-27T23:15:07.813088+00:00", "updated": "2026-10-28T21:47:58.075819+00:00", "vendors": ["golang", "golang$PRODUCT$net"], "weaknesses": ["CWE-770"]}