net/url: strict RFC 6874 validation for IPv6 zone identifiers by VenkatKwest · Pull Request #78570 · golang/go

VenkatKwest · 2026-04-08T01:52:12Z

net/url: strict RFC 6874 validation for IPv6 zone identifiers

This change updates the URL parser to strictly enforce the RFC 6874
ABNF grammar for IPv6 zone identifiers:
ZoneID = 1*( unreserved / pct-encoded )

Previously, net/url allowed various sub-delims and gen-delims (such
as ']', '!', '$', etc.) in the zone identifier. This allowed
malformed hosts like [::1%25]evil.com] to absorb text past the closing
bracket into the zone identifier.

By restricting the unescaped characters in encodeZone to only the
unreserved set (ALPHA / DIGIT / - / . / _ / ~), any
non-compliant characters will now correctly fail parsing unless they
are properly percent-encoded.

Fixes #78569

gopherbot · 2026-04-08T02:02:28Z

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gopherbot · 2026-04-08T02:12:26Z

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Patch Set 1:

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gopherbot · 2026-04-08T02:22:21Z

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gopherbot · 2026-04-08T03:22:44Z

Message from Nicholas Husin:

Patch Set 1: Commit-Queue+1

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gopherbot · 2026-04-08T03:22:45Z

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Patch Set 1:

Dry run: CV is trying the patch.

Bot data: {"action":"start","triggered_at":"2026-04-08T03:05:01Z","revision":"210f964a7d8bfbdc1092186c3d17eaf2e3687fb2"}

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gopherbot · 2026-04-08T03:32:39Z

Message from Nicholas Husin:

Patch Set 1: -Commit-Queue

(Performed by <GERRIT_ACCOUNT_60063> on behalf of <GERRIT_ACCOUNT_4321354>)

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gopherbot · 2026-04-08T03:32:39Z

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Patch Set 1:

This CL has failed the run. Reason:

Tryjob golang/try/gotip-linux-amd64-race has failed with summary (view all results):

go on master (change 763880)

To reproduce, try gomote repro 8685123813172675217.

Additional links for debugging:

go tool dist test -json output [shard 2]

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gopherbot · 2026-04-08T03:32:40Z

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Patch Set 1: LUCI-TryBot-Result-1

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gopherbot · 2026-04-08T05:31:11Z

This PR (HEAD: 8c03a17) has been imported to Gerrit for code review.

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gopherbot · 2026-04-08T05:41:21Z

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Patch Set 2:

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gopherbot · 2026-04-08T05:41:22Z

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Patch Set 1: Hold+1

Copied votes on follow-up patch sets have been updated:

Hold+1 has been copied to patch set 2 (copy condition: "is:ANY").

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gopherbot · 2026-04-08T05:51:17Z

This PR (HEAD: 6c6150b) has been imported to Gerrit for code review.

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gopherbot · 2026-04-08T06:00:57Z

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Patch Set 2:

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gopherbot · 2026-04-08T06:51:56Z

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Patch Set 3:

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gopherbot · 2026-04-08T06:51:56Z

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Patch Set 3:

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This change updates the URL parser to strictly enforce the RFC 6874 ABNF grammar for IPv6 zone identifiers: ZoneID = 1*( unreserved / pct-encoded ) Previously, net/url allowed various sub-delims and gen-delims (such as ']', '!', '$', etc.) in the zone identifier. This allowed malformed hosts like [::1%25]evil.com] to absorb text past the closing bracket into the zone identifier. By restricting the unescaped characters in encodeZone to only the unreserved set (ALPHA / DIGIT / "-" / "." / "_" / "~"), any non-compliant characters will now correctly fail parsing unless they are properly percent-encoded. Fixes golang#78569

gopherbot · 2026-04-08T11:58:52Z

This PR (HEAD: 2f28559) has been imported to Gerrit for code review.

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gopherbot · 2026-04-08T12:10:01Z

Message from Venkat Esan:

Patch Set 3:

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VenkatKwest force-pushed the fix-ipv6-greedy-bracket branch from 8c03a17 to 6c6150b Compare April 8, 2026 05:42

VenkatKwest changed the title ~~net/url: stop greedy matching of ] in IPv6 zone literals~~ net/url: forbid unescaped ']' in IPv6 zone identifiers Apr 8, 2026

VenkatKwest force-pushed the fix-ipv6-greedy-bracket branch from 6c6150b to 2f28559 Compare April 8, 2026 11:51

VenkatKwest changed the title ~~net/url: forbid unescaped ']' in IPv6 zone identifiers~~ net/url: strict RFC 6874 validation for IPv6 zone identifiers Apr 8, 2026

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