How severe is CVE-2007-4840?

CVE-2007-4840 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2007-4840 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2007-4840?

CVE-2007-4840 affects Php. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2007-4840?

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

When was CVE-2007-4840 published?

CVE-2007-4840 was published on 2007-09-12 and last updated on 2026-06-16.

CVE-2007-4840

CVE-2007-4840 is a medium-severity vulnerability in Php with a CVSS 2.0 base score of 5.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Php
Published: 2007-09-12
Last modified: 2026-06-16

Description

PHP 5.2.4 and earlier allows context-dependent attackers to cause a denial of service (application crash) via (1) a long string in the out_charset parameter to the iconv function; or a long string in the charset parameter to the (2) iconv_mime_decode_headers, (3) iconv_mime_decode, or (4) iconv_strlen function. NOTE: this might not be a vulnerability in most web server environments that support multiple threads, unless these issues can be demonstrated for code execution.

Frequently asked questions

What is CVE-2007-4840?: PHP 5.2.4 and earlier allows context-dependent attackers to cause a denial of service (application crash) via (1) a long string in the out_charset parameter to the iconv function; or a long string in the charset parameter to the (2) iconv_mime_decode_headers, (3) iconv_mime_decode, or (4) iconv_strlen function. NOTE: this might not be a vulnerability in most web server environments that support multiple threads, unless these issues can be demonstrated for code execution.
How severe is CVE-2007-4840?: CVE-2007-4840 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2007-4840 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2007-4840?: CVE-2007-4840 affects Php. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2007-4840?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2007-4840 published?: CVE-2007-4840 was published on 2007-09-12 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)