Phi 0.3.0 through 0.28.4 Permission Bypass via agent_spawn Workdir

Advisories

Phi 0.3.0 through 0.28.4 Permission Bypass via agent_spawn Workdir

severity: medium
date: 10/10/2026
Affecting: phi >= 0.3.0, <= 0.28.4
CVE: CVE-2026-108595
CWE: CWE-863 Incorrect Authorization
CVSS: 6.0
CVSS V4 Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References: https://hackmd.io/@haind/phi-subagent-workdir-workspace-escape
https://github.com/pulseaiclub/phi/blob/5b3cb440a7c58115ef64283a737a43299f2805a4/internal/tools/agenttool/agent.go#L106-L120
https://github.com/pulseaiclub/phi/blob/5b3cb440a7c58115ef64283a737a43299f2805a4/internal/agent/engine_runner.go#L52-L60
https://github.com/pulseaiclub/phi
Credit: HaiND from the Post and Telecommunication Institute of Technology
Description: Phi 0.3.0 through 0.28.4 contains a permission bypass vulnerability that allows spawned sub-agents to escape workspace_only_writes and readonly mode by supplying an unchecked workdir to agent_spawn. Attackers can plant prompt-injected instructions in processed content so the agent spawns a worker rooted elsewhere, causing unapproved file writes anywhere the user can write.

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