CVE-2026-82531 is a high-severity (CVSS 8.1) Code Injection vulnerability. No vendor fix is recorded yet; mitigation options are listed below.
Smarty before 4.5.8 and 5.x before 5.8.5 contains a code injection vulnerability where the top-level nocache_hash is never restored during extends:/multi-component template inheritance,…
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-82531.
Description
Smarty before 4.5.8 and 5.x before 5.8.5 contains a code injection vulnerability where the top-level nocache_hash is never restored during extends:/multi-component template inheritance, leaving it null. Attackers can supply assigned data containing a forged SmartyNocache marker that is copied verbatim into the regenerated PHP cache file, executing arbitrary PHP on include for remote code execution.
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-82531 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2026-82531 in your dependencies?
Find it across , including transitive dependencies.