PHP security advisory

XXE via libxml global state

CVE-2023-3823High 8.6 Published ext/libxml (DOM, SimpleXML, XML)

Also known as: GHSA-3qrf-m4j2-pcrr

PHP XML functions rely on libxml global state that other libraries in the same process can change, which can re-enable external entity loading and expose local files.

Affected versions

BranchAffectedFixed in
PHP 8.2< 8.2.98.2.9
PHP 8.1< 8.1.228.1.22
PHP 8.0< 8.0.308.0.30

Older branches: not assessed

Exploitation conditions

No special conditions are documented.

Remediation

Upgrade to 8.0.30, 8.1.22, 8.2.9 or a later release of your branch. If your branch is end-of-life, move to a supported branch. Distribution packages may carry a backported fix under an older version number; confirm with your vendor's security tracker.

A version number alone cannot prove patch status. Linux distributions and hosting providers often backport security fixes without changing the version. Check your vendor’s changelog.

Severity scores

CVSSSourceVector
8.6 v3.1CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L

References

Data provenance

Secondary sources · pending primary verification

Last reviewed: Oct 24, 2026 · Source

Notes: The CVE description says "8.2.* before 8.2.8"; the fix shipped in 8.2.9 together with 8.1.22 and 8.0.30.