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@renovate renovate bot commented Nov 27, 2025

This PR contains the following updates:

Package Change Age Confidence
valibot (source) 1.1.0 -> 1.2.0 age confidence

GitHub Vulnerability Alerts

CVE-2025-66020

Summary

The EMOJI_REGEX used in the emoji action is vulnerable to a Regular Expression Denial of Service (ReDoS) attack. A short, maliciously crafted string (e.g., <100 characters) can cause the regex engine to consume excessive CPU time (minutes), leading to a Denial of Service (DoS) for the application.

Details

The ReDoS vulnerability stems from "catastrophic backtracking" in the EMOJI_REGEX. This is caused by ambiguity in the regex pattern due to overlapping character classes.

Specifically, the class \p{Emoji_Presentation} overlaps with more specific classes used in the same alternation, such as [\u{1F1E6}-\u{1F1FF}] (regional indicator symbols used for flags) and \p{Emoji_Modifier_Base}.

When the regex engine attempts to match a string that almost matches but ultimately fails (like the one in the PoC), this ambiguity forces it to explore an exponential number of possible paths. The matching time increases exponentially with the length of the crafted input, rather than linearly.

PoC

The following code demonstrates the vulnerability.

import * as v from 'valibot';

const schema = v.object({
  x: v.pipe(v.string(), v.emoji()),
});

const attackString = '\u{1F1E6}'.repeat(49) + '0';

console.log(`Input length: ${attackString.length}`);
console.log('Starting parse... (This will take a long time)');

// On my machine, a length of 99 takes approximately 2 minutes.
console.time();
try {
  v.parse(schema, {x: attackString });
} catch (e) {}
console.timeEnd();

Impact

Any project using Valibot's emoji validation on user-controllable input is vulnerable to a Denial of Service attack.

An attacker can block server resources (e.g., a web server's event loop) by submitting a short string to any endpoint that uses this validation. This is particularly dangerous because the attack string is short enough to bypass typical input length restrictions (e.g., maxLength(100)).

Recommended Fix

The root cause is the overlapping character classes. This can be resolved by making the alternatives mutually exclusive, typically by using negative lookaheads ((?!...)) to subtract the specific classes from the more general one.

The following modified EMOJI_REGEX applies this principle:

export const EMOJI_REGEX: RegExp =
  // eslint-disable-next-line redos-detector/no-unsafe-regex, regexp/no-dupe-disjunctions -- false positives
  /^(?:[\u{1F1E6}-\u{1F1FF}]{2}|\u{1F3F4}[\u{E0061}-\u{E007A}]{2}[\u{E0030}-\u{E0039}\u{E0061}-\u{E007A}]{1,3}\u{E007F}|(?:\p{Emoji}\uFE0F\u20E3?|\p{Emoji_Modifier_Base}\p{Emoji_Modifier}?|(?![\p{Emoji_Modifier_Base}\u{1F1E6}-\u{1F1FF}])\p{Emoji_Presentation})(?:\u200D(?:\p{Emoji}\uFE0F\u20E3?|\p{Emoji_Modifier_Base}\p{Emoji_Modifier}?|(?![\p{Emoji_Modifier_Base}\u{1F1E6}-\u{1F1FF}])\p{Emoji_Presentation}))*)+$/u;

Configuration

📅 Schedule: Branch creation - "" (UTC), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.


  • If you want to rebase/retry this PR, check this box

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renovate bot commented Nov 27, 2025

Branch automerge failure

This PR was configured for branch automerge. However, this is not possible, so it has been raised as a PR instead.


  • Branch has one or more failed status checks

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pkg-pr-new bot commented Nov 28, 2025

Open in StackBlitz

npm i https://pkg.pr.new/mmkal/trpc-cli@162

commit: 20ba51b

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renovate bot commented Nov 28, 2025

Edited/Blocked Notification

Renovate will not automatically rebase this PR, because it does not recognize the last commit author and assumes somebody else may have edited the PR.

You can manually request rebase by checking the rebase/retry box above.

⚠️ Warning: custom changes will be lost.

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