smarty/smarty security advisory

CVE-2026-62996: Smarty Security stream restriction bypass through stream: resource

CVE-2026-62996 is a medium-severity path traversal vulnerability in the PHP package smarty/smarty (CVSS 6.9), published 7 August 2026. It is fixed in 5.8.4; earlier versions are affected. Exploiting it needs an admin-level account.

medium 6.9 published 2026-08-07 · updated 2026-10-24

Affected versions: >= 5.0.0, < 5.8.4
Fixed in: 5.8.4
Newest release: 5.8.5
Severity: Medium · CVSS 6.9
Type: Path traversal / file read
CWE-22
Exploited in the wild: Not on the CISA KEV list
checked 2026-11-04

Is your smarty/smarty version affected?

Run composer show smarty/smarty in your project, then enter the version. We check it against this and every other known smarty/smarty advisory.

Who can exploit CVE-2026-62996

Access: A high-privilege account in the app, such as an admin.

CVSS vector (scored by GitHub): CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Your app is only exposed if it uses the affected part of smarty/smarty. The advisory below says which part that is. If you are not sure, upgrade anyway: it costs less than finding out.

How to fix CVE-2026-62996 in smarty/smarty

Find the installed version: composer show smarty/smarty. If you never required it yourself, composer why smarty/smarty shows which package pulls it in.
Update it: composer update smarty/smarty --with-all-dependencies. You need 5.8.4 or newer.
If Composer will not go that high, your composer.json constraint is holding it back. Widen it (for example "smarty/smarty": "^5.8.4" if you can take that version), or upgrade the package that requires it.
Run composer audit. It reads the same advisory data and should no longer list CVE-2026-62996.
Commit composer.lock and deploy it. On the server, run composer install --no-dev from the lock file, not composer update.

If you cannot upgrade yet

General hardening for path traversal issues while the upgrade waits. None of it replaces the fix.

Validate file names against an allow-list and reject paths containing ../ or absolute paths.
If your app does not use the affected feature, note that in your audit, but still plan the upgrade.

The CVE-2026-62996 advisory

Smarty is a template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. From 5.0.0 until 5.8.4, Smarty's stream: resource-name handling does not adequately restrict which PHP stream wrappers and filter chains can be referenced from a template, allowing a php://filter-wrapped resource name to be used to read the contents of arbitrary local files accessible to the PHP process. An attacker able to author or influence a template's resource reference could exploit this to disclose sensitive file contents outside the intended template/config scope. This issue is fixed in version 5.8.4.

Description from the CVE record, published by GitHub (the CVE Numbering Authority), via the NVD entry for CVE-2026-62996. Advisory title: “Smarty Security stream restriction bypass through stream: resource”.

References

GitHub advisory GHSA-rjhh-76wf-8xmw github.com
Fix commit 3c9f77a github.com
Pull request #1195 github.com
Release v5.8.4 github.com

Other smarty/smarty advisories

medium CVE-2026-62993: Smarty: SSRF via redirect bypass of trusted_uri using {fetch} 2026-09-01
medium CVE-2026-62992: Smarty: Symlink path traversal out of trusted directories 2026-08-07
high CVE-2024-35226: Smarty vulnerable to PHP Code Injection by malicious attribute in extends-tag 2024-05-29
high CVE-2023-28447: Cross site scripting vulnerability in Javascript escaping 2023-03-28
medium CVE-2018-25047: Smarty_function_mailto - JavaScript injection in eval function 2022-09-14
high CVE-2022-29221: PHP Code Injection by malicious block or filename 2022-05-17

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Where this data comes from

Affected and fixed versions: the Packagist security advisories API (GitHub Advisory Database and FriendsOfPHP), the same data composer audit uses. Synced 2026-11-03.
Description, score, weakness and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
Exploited-in-the-wild status: the CISA Known Exploited Vulnerabilities catalog, checked 2026-11-04.
Compiled by Daniel Lasek at Laskyr from the sources above. The summary, “who can exploit it”, “how to fix it” and hardening sections are our plain-English reading of the record and are generated from it. The quoted description is the record's own text. Spot an error? Tell us.