high CVSS 7.8

CVE-2026-45136·Python vulnerability

claude-code-cache-fix is a cache optimization proxy for Claude Code. From 3.5.0 to before 3.5.2, tools/quota-statusline.sh (introduced in v3.5.0) interpolates Claude Code's hook stdin payload directly into a Python triple-quoted string literal. A ''' byte sequence in any user-controlled field of the payload closes the literal early and lets following bytes execute as Python in the user's Claude Code process. This vulnerability is fixed in 3.5.2.

Severity
high
Software
Python
Fixed in
3.5.2
Published
2026-05-27

Affected versions

From: 3.5.0

Until: 3.5.2

Fixed in: 3.5.2

How to fix this CVE

Update the claude-code-cache-fix component to version 3.5.2 or later to remediate this critical string interpolation vulnerability. The affected versions (3.5.0–3.5.1) allow arbitrary Python code execution through malformed payload injection in the quota-statusline.sh script. Immediately patch your Python environment and verify the update completion before resuming Claude Code operations.

sudo dnf check-update && sudo dnf upgrade python3 && pip install --upgrade claude-code-cache-fix>=3.5.2

Defensia detects this vulnerability

How to check if you are affected

  1. Check installed version: pip show claude-code-cache-fix | grep Version
  2. Verify if quota-statusline.sh exists and is active: ls -la ~/.claude/tools/quota-statusline.sh (or appropriate installation path)
  3. Search logs for triple-quote sequences in Claude Code hook payloads: grep -r "'''" ~/.claude/logs/ or journalctl -u claude-code | grep "'''"
  4. Confirm patch applied: pip show claude-code-cache-fix | grep Version should report 3.5.2 or later

FAQ

What is CVE-2026-45136?

This vulnerability exists in the quota-statusline.sh script bundled with claude-code-cache-fix versions 3.5.0–3.5.1, where user-controlled hook payload data is directly interpolated into a Python string literal without escaping, allowing attackers to inject and execute arbitrary Python code by crafting payloads containing triple-quote sequences.

Is CVE-2026-45136 being actively exploited?

No, this vulnerability is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, and no public exploits are currently available, though the attack surface depends on whether users expose Claude Code hooks to untrusted input sources.

What versions of Python are affected by CVE-2026-45136?

claude-code-cache-fix versions 3.5.0 through 3.5.1 are vulnerable; the fix is available in version 3.5.2 and later.

How do I check if my server is vulnerable to CVE-2026-45136?

Run: pip show claude-code-cache-fix | grep Version. If the version is 3.5.0 or 3.5.1, your installation is vulnerable and requires immediate patching.

Does Defensia detect CVE-2026-45136?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If claude-code-cache-fix is installed on a monitored server, CVE-2026-45136 will appear in your dashboard with remediation steps.

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References

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