CVE-2026-82531: Smarty before 4.5.8 and 5.x before 5.8.5 PHP Code Injection via extends: Inheritance Cache
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.8%
EPSS score, percentile 57.2 of all scored records. A probability estimated by FIRST, not a report of exploitation.
CISA's SSVC assessment in the CVE record lists exploitation as poc.
- How severe?
- 9.2 Critical
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- before 4.5.8
- from 5.0.0 to before 5.8.5
Unaffected 4.5.8; 5.8.5
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
What to do
Advisories and patches
- github.com
- github.com
- GitHub Security Advisory (GHSA-3w63-v7pm-cq9x)
- smarty v5.8.5 Release Notes
- smarty v4.5.8 Release Notes
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | before 4.5.8 |
| Affected | from 5.0.0 to before 5.8.5 |
| Unaffected | 4.5.8 |
| Unaffected | 5.8.5 |
Versions not listed are: unaffected.
Versions the record lists as unaffected: 4.5.8, 5.8.5.
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
About this vulnerability
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 executio…
Summary: CVE record, as of .
- CISA has not added CVE-2026-82531 to its Known Exploited Vulnerabilities (KEV) catalog, as of 28 Oct 2026.
- The CVE record was published on 6 Oct 2026.
- The CVE record carries a CVSS v4.0 base score of 9.2 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.8% (percentile 57.2), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation poc, automatable no, technical impact total.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.
Description
Smarty before 4.5.8 and 5.x before 5.8.5 PHP Code Injection via extends: Inheritance Cache
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.
Source: CVE List V5 (CVE Program), cve_2026-10-29_0000Z, as of . About the data.
Weakness
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published |