Activepieces CVE-2026-48499

Requires an authenticated flow-author account (CVSS PR:L) with the ability to create or edit a Code piece, and the target Activepieces deployment must be multi-tenant with the worker running in shared SANDBOX_PROCESS execution mode so that another tenant's read-write cached flow and code files reside on the same worker filesystem. The concrete trigger is an unsanitized path segment supplied through the Code piece that resolves into a co-tenant's cache directory. Exploitation is limited by these factors: the attacker cannot be fully anonymous (login required), a victim tenant must share the same worker, and to achieve code execution the victim must subsequently run the tampered flow. Single-tenant self-hosted installs, or deployments that place each tenant on a dedicated isolated worker, are not exposed to the cross-tenant impact even though the path-handling bug is present.

The vendor CVSS 4.0 score is 9.3 (Critical) with vector AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N: network-reachable, low complexity, no attack requirements or user interaction, requiring only low privileges (PR:L, i.e. an authenticated flow author). The high subsequent-system metrics (SC:H/SI:H) correctly capture that impact crosses a security boundary into other tenants. EPSS is not provided in the input, so exploitation-probability cannot be quantified here. No POC/exploit code and no KEV listing were supplied, so exploitation status is 'no public exploit identified at time of analysis' - this is not confirmed active exploitation. The main gating factor is that the attacker must be a legitimate authenticated user of the platform and must be co-located on the same worker as a victim tenant, which makes this most acute for shared/multi-tenant hosted Activepieces deployments rather than single-tenant self-hosts. Net: a genuine high priority for any multi-tenant Activepieces operator (real tenant-isolation break with read and write primitives), but lower practical risk for single-tenant installs where no foreign tenant shares the worker. Note the CWE (information disclosure) understates the integrity/RCE-on-victim aspect described in the advisory - weight the description over the CWE class here.

An attacker signs up for (or already holds) a low-privilege flow-author account on a shared, multi-tenant Activepieces instance. They create a Code piece whose file path includes an unsanitized traversal segment, causing the worker to read another tenant's cached code and embedded secrets and to overwrite that tenant's cached code with attacker-controlled JavaScript. When the victim tenant next runs the affected flow, the attacker's code executes in the victim's context. No POC was provided in the intelligence, and the low CVSS complexity (AC:L, no user interaction) means the technique is straightforward once tenant co-location on a worker is achieved.