CVE-2008-5557: n/a vulnerability

CVE-2008-5557: Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter_htmlent.c in the mbstring extension in...

Heap-based buffer overflow in ext/mbstring/libmbfl/filters/mbfilter_htmlent.c in the mbstring extension in PHP 4.3.0 through 5.2.6 allows context-dependent attackers to execute arbitrary code via a crafted string containing an HTML entity, which is not properly handled during Unicode conversion, related to the (1) mb_convert_encoding, (2) mb_check_encoding, (3) mb_convert_variables, and (4) mb_parse_str functions.

UnknownCVSS not scoredNot KEV-listedUpdatedAug 7, 2024, 10:56 UTC (UTC+00:00)

Security readout for executives and security teams

This is an old PHP mbstring memory-safety flaw. A specially crafted string containing an HTML entity could corrupt heap memory during Unicode conversion and may allow arbitrary code execution. Business risk is mainly in legacy PHP estates still running PHP 4.3.0 through 5.2.6 or old vendor packages. Exposure is most likely on unsupported legacy PHP 4.x or 5.2.6-and-earlier systems with mbstring enabled and application paths that process untrusted strings through the affected conversion functions. Prioritize remediation if any business system still runs legacy PHP with mbstring. The vulnerability is old, but code execution impact makes remaining exposure unacceptable, especially for internet-facing applications. Mitigation focus: Upgrade PHP or vendor PHP packages beyond the affected versions.; Apply relevant Apple, Red Hat, Fedora, SUSE, HP, or rPath advisories where applicable.; Check PHP 5.2.7 changelog and vendor guidance for fixed package details..

Prepared: Jun 28, 2026, 11:41 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Dec 23, 2008, 18:13 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
FEDORA-2009-3768CVE reference · vendor-advisory, x_refsource_FEDORA
FEDORA-2009-3848CVE reference · vendor-advisory, x_refsource_FEDORA
php-multibyte-bo(47525)CVE reference · vdb-entry, x_refsource_XF
oval:org.mitre.oval:def:10286CVE reference · vdb-entry, signature

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

n/an/an/aListed

Weakness

CWE details

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