hybrid-xss:script-tag drops the closing-tag requirement, becoming byte-identical
to llm-security's RegExp.source at b1ba1fb (injection-patterns.mjs:170). Verified
by compiling both, not by reading them.
Why this does not breach behaviour-preservation: that invariant forbids commons
from CORRECTING seed data it believes is wrong. It does not forbid re-reading the
source after the source itself moved and its owner asked. This file's declared
provenance is llm-security's injection table, and being loadable verbatim by that
table's owner is the one thing it exists to do. The standing alternative was a
per-pattern override in their loader — a published core its own source repository
could not load as published.
Direction is what makes it safe: the new form matches a strict superset of the
old, so it can add matches and cannot introduce a false negative. The reverse
change would not have been adoptable on this reasoning.
NOT decided by the 2-of-3 majority across the three ports. A count of
implementations is not a mandate over detection data; the provenance argument
would hold with the guard on either side. Operator decision, 2026-08-11, on
llm-security's blocking coord request (their 10:46:28Z message, step-4 swap
parked behind it).
Measured collateral: none. Full corpus run under both patterns — 84/84
lexicon-scoped cases pass under 0.7.0, and exactly one case's finding set differs
between the forms. The widening added no finding to any other case's input.
source_fidelity keeps patterns_byte_identical_to_source at 83 and gains the field
it was missing: byte_identical_against_commit: b1ba1fb. Against the original
extraction commit b0de0ca the count is now 82/83, recorded explicitly.
post_extraction_drift is marked resolved and carries before/after pattern text,
so a consumer diffing against either commit has a coordinate for what it finds.
The divergence row is closed on the closing-tag axis after reversing twice in
three days. What stays open is the one-byte span difference: the guard excludes
`<` from its negated class and the other two do not, so `<script <x>` matches
commons and llm-security but not the guard. Measured by compiling all three.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HuudQLGMyMenuyeZk8fKs5
Kjell Tore Guttormsen
c1b2385de6