CVE-2026-7568

In PHP versions 8.2.* before 8.2.31, 8.3.* before 8.3.31, 8.4.* before 8.4.21, and 8.5.* before 8.5.6, the metaphone() function in ext/standard/metaphone.c uses a signed int variable to track the current position within the input string. If a string longer than 2,147,483,647 bytes is passed, a signed integer overflow occurs, resulting in undefined behavior. This can lead to an out-of-bounds read, causing a segmentation fault or access to unrelated memory, and may affect the availability of the PHP process.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Name	Vendor	Start Version	End Version
Php	Php	8.2.0 (including)	8.2.31 (excluding)
Php	Php	8.3.0 (including)	8.3.31 (excluding)
Php	Php	8.4.0 (including)	8.4.21 (excluding)
Php	Php	8.5.0 (including)	8.5.6 (excluding)
Red Hat Enterprise Linux 10	RedHat	php8.4-0:8.4.21-1.el10_2	*
Red Hat Enterprise Linux 10	RedHat	php-0:8.3.31-1.el10_2	*
Red Hat Enterprise Linux 8	RedHat	php:8.2-8100020260521052503.f7998665	*
Red Hat Enterprise Linux 8	RedHat	php:7.4-8100020260604072603.f7998665	*
Red Hat Enterprise Linux 9	RedHat	php:8.3-9080020260521113736.9	*
Red Hat Enterprise Linux 9	RedHat	php:8.2-9080020260521080715.9	*
Red Hat Enterprise Linux 9	RedHat	php-0:8.0.30-6.el9_8	*
Php7.0	Ubuntu	esm-infra/xenial	*
Php8.1	Ubuntu	jammy	*
Php8.3	Ubuntu	noble	*
Php8.3	Ubuntu	upstream	*
Php8.4	Ubuntu	questing	*
Php8.4	Ubuntu	upstream	*
Php8.5	Ubuntu	devel	*
Php8.5	Ubuntu	resolute	*
Php8.5	Ubuntu	upstream	*

Potential Mitigations

Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

https://cwe.mitre.org/data/definitions/540.html

NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-7568
CWE	https://cwe.mitre.org/data/definitions/125.html

Out-of-bounds Read

Weakness

Affected Software

Potential Mitigations

References

CVE-2026-7568

Out-of-bounds Read

Weakness

Affected Software

Potential Mitigations

Related Attack Patterns

References