Fix Monolog — CVE-2021-41196 HIGH
Fix CVE-2021-41196 (HIGH) in Monolog for PHP. Paste your composer.json into PackageFix and get a patched version — no CLI, no signup. Log injection via crafted http request headers.
⚠ Vulnerability
CVE-2021-41196 (HIGH) — log injection via crafted HTTP request headers in Monolog below ^3.5.
Vulnerable — composer.json
"monolog/monolog": "^2.0"
Fixed — composer.json
"monolog/monolog": "^3.5"
✓ Fix
Update Monolog to ^3.5 and run composer install.
Paste your manifest — get back a fixed version with all CVEs patched in seconds.
Open PackageFix →No signup · No CLI · No GitHub connection · Runs 100% in your browser
CVE Details
| Field | Value |
|---|---|
| CVE ID | CVE-2021-41196 |
| Severity | HIGH |
| Package | Monolog (PHP) |
| Safe version | ^3.5 |
| CISA KEV | — |
| Description | Log injection via crafted http request headers |
Frequently Asked Questions
What is CVE-2021-41196?
CVE-2021-41196 is a HIGH severity vulnerability in Monolog (PHP) that allows log injection via crafted HTTP request headers. Update to ^3.5 or later.
How do I fix CVE-2021-41196 in Monolog?
Update Monolog to version ^3.5 in your composer.json and run composer install.
Is CVE-2021-41196 being actively exploited?
Check packagefix.dev — the CISA KEV catalog updates daily.
How do I verify the fix for CVE-2021-41196?
After updating, paste your composer.json into PackageFix again. If CVE-2021-41196 no longer appears in the CVE table, the fix is applied.