How severe is CVE-2007-1521?

CVE-2007-1521 has a CVSS 2.0 base score of 6.8, rated medium severity.

Is CVE-2007-1521 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2007-1521?

CVE-2007-1521 affects Php. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2007-1521?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2007-1521 published?

CVE-2007-1521 was published on 2007-03-20 and last updated on 2026-06-16.

CVE-2007-1521

CVE-2007-1521 is a medium-severity vulnerability in Php with a CVSS 2.0 base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 2.0 base score 6.8)
EPSS exploit prediction: 8% (94th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Php
Published: 2007-03-20
Last modified: 2026-06-16

Description

Double free vulnerability in PHP before 4.4.7, and 5.x before 5.2.2, allows context-dependent attackers to execute arbitrary code by interrupting the session_regenerate_id function, as demonstrated by calling a userspace error handler or triggering a memory limit violation.

Frequently asked questions

What is CVE-2007-1521?: Double free vulnerability in PHP before 4.4.7, and 5.x before 5.2.2, allows context-dependent attackers to execute arbitrary code by interrupting the session_regenerate_id function, as demonstrated by calling a userspace error handler or triggering a memory limit violation.
How severe is CVE-2007-1521?: CVE-2007-1521 has a CVSS 2.0 base score of 6.8, rated medium severity.
Is CVE-2007-1521 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 8% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-1521?: CVE-2007-1521 affects Php. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2007-1521?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-1521 published?: CVE-2007-1521 was published on 2007-03-20 and last updated on 2026-06-16.

References

Affected products (1)

cpe:2.3:a:php:php:*:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

222.99.52.202 (ipv4-addr)
90.160.135.217 (ipv4-addr)
62.36.19.42 (ipv4-addr)
62.36.19.41 (ipv4-addr)