{"id":"CVE-2026-62331","aliases":["GHSA-48v2-6jcm-fc99"],"url":"https://o3.security/vulnerability/CVE-2026-62331","summary":"praktor: Telegram upload traversal permits persistent agent instruction injection","details":"### Impact\n\nA remote Telegram user can write files to arbitrary paths inside an agent's persistent workspace volume (`praktor-wk-<workspace>`, mounted at `/workspace/agent`), escaping the documented `uploads/` directory.\n\nThe attacker controls the Telegram document filename, which was concatenated into the destination path without sanitization (`internal/telegram/bot.go`, at both upload sites) and resolved with `path.Join`, which collapses `../` sequences. A filename like `../../../CLAUDE.md` resolved to the root of the agent workspace volume, outside `uploads/`.\n\nBecause the agent workspace is the persistent working directory the Claude agent reads from and operates on across runs, writing outside `uploads/` lets an attacker plant or overwrite files the agent later consumes — e.g. `CLAUDE.md`, agent instruction/skill/hook files, or other config under `/workspace/agent`. This turns a file upload into a stored injection into the agent's instruction/execution surface (CWE-22 path traversal escalating to stored instruction injection).\n\n### Reachability\n\nBy default the bot has no user allowlist (`allow_from: []` means \"allow all\"), so the only precondition is that a user can message the bot. No authentication or prior privilege is required.\n\n### Affected versions\n\nThrough `v0.9.0` (and HEAD `3902d29`).\n\n### Patched versions\n\n`v0.9.1`, containing PR #228.\n\n### Workarounds\n\nRestrict `telegram.allow_from` to trusted user IDs to limit who can send uploads to the bot. Upgrading to `v0.9.1` is the recommended fix.\n\n### Fix (defense in depth)\n\n- `internal/telegram/bot.go`: apply `path.Base()` to the attacker-controlled filename at both upload sites, stripping directory components and `..`.\n- `internal/container/manager.go`: `WriteVolumeBytes` now rejects any path that escapes `/vol` after `path.Join`, protecting future callers.\n\n### Credit\n\nReported privately by [tonghuaroot](https://github.com/tonghuaroot), who provided a detailed root-cause analysis, a deployed end-to-end proof of concept against the real `container.Manager`, and fix verification.","published":"2026-10-30T19:00:25.777Z","modified":"2026-11-01T02:47:31.346974148Z","cvss":{"score":8.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Go","name":"github.com/mtzanidakis/praktor","fixedVersion":"0.9.1"}],"fix":{"url":"https://github.com/mtzanidakis/praktor/commit/c3731eeda01c0b3ec1dbd13cccd5a147c3182141","label":"mtzanidakis/praktor@c3731ee"},"references":[{"type":"WEB","url":"https://github.com/mtzanidakis/praktor/releases/tag/v0.9.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/62xxx/CVE-2026-62331.json"},{"type":"ADVISORY","url":"https://github.com/mtzanidakis/praktor/security/advisories/GHSA-48v2-6jcm-fc99"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-62331"},{"type":"FIX","url":"https://github.com/mtzanidakis/praktor/commit/c3731eeda01c0b3ec1dbd13cccd5a147c3182141"},{"type":"FIX","url":"https://github.com/mtzanidakis/praktor/pull/228"},{"type":"PACKAGE","url":"https://github.com/mtzanidakis/praktor"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-11-01T02:47:31.346974148Z"}}