False positive java:S8786 on simple trailing-digits regex Pattern.compile("\\d+$")

Rules and Languages Report False-positive / False-negative...
1

Product

  • SonarLint for Eclipse 12.4.0.84771
  • Eclipse 2026-06 (4.40)
  • Java 17

Rule

java:S8786 – Regular expressions should not cause non-linear backtracking.

Problem

SonarLint reports java:S8786 on the following regex:

import java.util.regex.Pattern;

class Test {
    private static final Pattern NUMBER_PATTERN =
            Pattern.compile("\\d+$");
}

The issue is reported on the Pattern.compile(...) call.

I believe this is a false positive because the pattern consists only of:

  • a single character class (\d)
  • one greedy quantifier (+)
  • an end-of-string anchor ($)

There are no nested quantifiers, alternations, optionals or lookarounds that could lead to non-linear backtracking.

I also tried the following equivalent patterns, all of which trigger the same warning:

Pattern.compile("(\\d+)$");
Pattern.compile("\\d++$");
Pattern.compile("[0-9]+$");
Pattern.compile("\\p{Digit}+$");

Could you please confirm whether this is a false positive?

Thanks!