semantic-router exposed to compromised litellm wheel (CVE-2026-42208) via unbounded transitive pin

Overview

Impact

semantic-router versions 0.1.8 through 0.1.14 declare litellm>=1.61.3 with no upper bound. During the window in which litellm==1.82.8 was the latest release on PyPI, a fresh install of any affected semantic-router version could resolve to that compromised wheel.

The malicious litellm==1.82.8 wheel ships a litellm_init.pth file that executes on Python interpreter startup — no import required. It collects and exfiltrates:

• Process environment variables
• AWS / GCP / Azure credentials
• SSH keys, Kubernetes configs, shell history
• Database credentials and CI/CD secrets
• Cryptocurrency wallets

Stage-two payload encrypts the collected data (AES-256 + embedded RSA pubkey) and POSTs it to https://models.litellm.cloud/.

See upstream: BerriAI/litellm#24512 and CVE-2026-42208.

Patches

Fixed in semantic-router 0.1.15, which raises the floor to litellm>=1.83.7.

Workarounds

If developers cannot upgrade immediately:

• Pin litellm>=1.83.7,!=1.82.8 explicitly in their own project.
• Audit site-packages/ for litellm_init.pth and delete if present.
• Rotate any credentials reachable from environments where an affected install ran.

Credit

Upstream report and triage by the litellm maintainers — see issue #24512.

One caveat before publishing

CVE-2026-42208 specifically names 1.82.8. Pip's resolver picks "latest matching", so the real affected blast radius for semantic-router is users who ran pip install during the window that 1.82.8 was on PyPI — not everyone who ever installed 0.1.8–0.1.14. The advisory is still correct (an affected install could have pulled the bad wheel), but consider whether a Severity: Critical / Exploitability: time-bounded note would help downstream readers understand the exposure model.

Affected packages

• semantic-router >= 0.1.8, < 0.1.15

Remediation

Upgrade to a patched release:

• semantic-router 0.1.15