OWASP's Top 10 for LLM Applications 2026 renumbered the list; only LLM01
and LLM02 kept their meaning. Every finding's `owasp` was written against
2025 with no year, so EchoLeak findings said LLM05, which in 2026 means
Data and Model Poisoning. Row 2 of the 2026 done-criterion counted 95
such sites at 6702d7a (82 old meaning, 13 wrong); it is now 0.
- Producers name the risk, never the number: one table (`_owasp.py`)
owns `LLMnn:2026`. The vendored lexicon stays byte-equal with commons
and gets its year where the finding is made; a commons number whose
meaning moved between editions raises instead of being guessed.
- Mechanical map from the 2025 meaning (verified against the publisher
in session 1): LLM05 -> LLM10:2026, LLM06 -> LLM03:2026,
LLM10 -> LLM06:2026, LLM08 -> LLM09:2026, LLM04 -> LLM05:2026.
The 13 wrong-meaning sites, judged:
- Factual poisoning (PoisonedRAG gap, and the test that follows it):
LLM05:2026. The 2026 text names "RAG Knowledge Base Poisoning" as its
example 6. It said LLM09, which was Misinformation.
- Fail-secure (README row, matrix row): no number. It is the guard's own
failure semantics; no edition describes it. Was LLM10.
- Parser-surface refusals (nested mapping, block scalar, quoted flow
element, off-allowlist key): no number. Refusing a shape the parser
would have to interpret is not resource consumption. Was LLM10. The
anchor and merge-key rows stay LLM06:2026 (alias expansion is DoS).
- `resource` URL and cross-link scheme validation (4): no number. They
validate received bundle metadata; LLM10:2026 is about model output
and says input validation belongs to LLM01. Was LLM05.
- `_raise_case` default (OKF path traversal, absolute path, reserved
name, non-.md, bundle escape): no number. None is prompt injection.
Was LLM01.
A doubtful number would be the misreading the year exists to prevent,
so `Case.owasp` is now Optional and the matrix prints "-".
Self-safety (input caps, ReDoS) keeps LLM06:2026: the 2026 text, read at
the publisher, covers "input flood ... exploiting processing
inefficiencies" and application-side rechunking. The README's LLM09
anchor (Misinformation) is dropped; it was the factual-poisoning row.
The permanent test (tests/test_catalog_numbers.py) fails on an old or
wrong number, on a number without the year outside the vendored
lexicon, and on any finding the coverage matrix drives whose `owasp`
lacks the newest year; "newest" is read from the catalog register. The
census holds its wrong-rules to their counts at the frozen revision
only, so the frozen listing (da1aa0fa...6f) is unchanged.
Kjell Tore Guttormsen
1c6816cdfe