phpwarden
FeaturesComparePricingAdvisoriesBlogDocsChangelogLog in
Log inStart free

CVE-2021-41270: CSV Injection in symfony/serializer

medium Affects symfony/serializer, symfony/symfony. Feed 2026.10.29.1, updated 2026-10-28; published ; advisory modified .

CSV Injection in symfony/serializer

Package
symfony/serializer Composer
Affected versions
>=5.0.0 and <5.3.12 or >=4.1.0 and <4.4.35 or >=4.1.0 and <4.2.0 or >=4.2.0 and <4.3.0 or >=4.3.0 and <4.4.0 or >=4.4.0 and <4.4.35 or >=5.0.0 and <5.1.0 or >=5.1.0 and <5.2.0 or >=5.2.0 and <5.3.0 or >=5.3.0 and <5.3.12
Fixed in
5.3.12, 4.4.35
Severity
medium  CVSS 6.5
Exploitation
not on CISA KEV · EPSS 1% (72.4th percentile)
Published
2021-11-24
Source
osv.dev

References

CSV Injection in symfony/serializer

Package
symfony/symfony Composer
Affected versions
>=4.1.0 and <4.4.35 or >=5.0.0 and <5.3.12 or >=4.1.0 and <4.2.0 or >=4.2.0 and <4.3.0 or >=4.3.0 and <4.4.0 or >=4.4.0 and <4.4.35 or >=5.0.0 and <5.1.0 or >=5.1.0 and <5.2.0 or >=5.2.0 and <5.3.0 or >=5.3.0 and <5.3.12
Fixed in
4.4.35, 5.3.12
Severity
medium  CVSS 6.5
Exploitation
not on CISA KEV · EPSS 1% (72.4th percentile)
Published
2021-11-24
Source
osv.dev

References

CWE-1236
NVD recordsymfony/serializer advisoriessymfony/symfony advisories

Am I affected?

Find out in one command. phpwarden checks your composer.lock against this advisory and 20,000+ others, ranked by real-world exploitation (CISA KEV + EPSS). Free, offline, open data.

# one-time install
pip install phpwarden

# then
phpwarden deps composer.lock

Or keep it checked automatically: GitHub Action · pre-commit hook · GitLab CI · Laravel artisan command

Install docs   How findings are ranked

Related advisories