fix: Fix uncontrolled recursion DoS in parser.py#468
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Adds a configurable maximum nesting depth (default 100) to prevent RecursionError when parsing deeply nested arrays or inline tables. When the limit is exceeded, a ParseError is raised instead of allowing unbounded recursion that crashes the process. Fixes python-poetry#459 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Hey sorry I just now seen It failed 2 checks, I will try and look in to it and get a fix sometime soon. |
arp242
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Recently there have been a few TOML implementations that have added a nesting limit depth to prevent using up huge amount of CPU/memory with a document like "a.«10,000 more» = 1". For example: hukkin/tomli#286 python-poetry/tomlkit#468 BurntSushi/toml@2e90ced6 There's probably more. In a casual quick look, many implementations already have such a limit and if they don't, they probably should. I added a comment in the toml-test README for it, but I think mentioning it in the spec would also be useful. If only to set a recommended lower limit like we do for 64bit ints. This is helpful both for implementation authors (as a reminder they should add such a limit) and users (as a reminder there may be a limit). For example BurntSushi/toml has never had such a limit until recently, even though I've always known this sort of thing is a problem. I ... just never thought of it. This would have been fixed years ago if there had been a comment in the spec. That's probably the same for tomli.
arp242
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May 24, 2026
Recently there have been a few TOML implementations that have added a nesting limit depth to prevent using up huge amount of CPU/memory with a document like "a.«10,000 more» = 1". For example: hukkin/tomli#286 python-poetry/tomlkit#468 BurntSushi/toml@2e90ced6 There's probably more. In a casual quick look, many implementations already have such a limit and if they don't, they probably should. I added a comment in the toml-test README for it, but I think mentioning it in the spec would also be useful. If only to set a recommended lower limit like we do for 64bit ints. This is helpful both for implementation authors (as a reminder they should add such a limit) and users (as a reminder there may be a limit). For example BurntSushi/toml has never had such a limit until recently, even though I've always known this sort of thing is a problem. I ... just never thought of it. This would have been fixed years ago if there had been a comment in the spec. That's probably the same for tomli.
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Adds a configurable maximum nesting depth (default 100) to prevent RecursionError when parsing deeply nested arrays or inline tables. When the limit is exceeded, a ParseError is raised instead of allowing unbounded recursion that crashes the process.
Fixes #459