CVE-2026-6722: PHP remote code execution (CVSS 9.8)

Description

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 SOAP extension's object deduplication mechanism stores pointers to PHP objects in a global map without incrementing their reference counts. When an apache:Map node contains duplicate keys, processing the second entry overwrites the first in the temporary result map, freeing the original PHP object while its stale pointer remains in the map. A subsequent href reference to the freed node can copy the dangling pointer into the result. As PHP string allocations can reclaim the freed memory region, an attacker with control over the SOAP request body can exploit this use-after-free to achieve remote code execution.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

PHP≥ 8.2.0 < 8.2.31 · ≥ 8.3.0 < 8.3.31 · ≥ 8.4.0 < 8.4.21 · ≥ 8.5.0 < 8.5.6

Remediation

Fixed in

PHP≥ 8.2.31

Patch & vendor advisories

https://github.com/php/php-src/security/advisories/GHSA-85c2-q967-79q5

References

and 1 more references

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2026-6722 being actively exploited?

CVE-2026-6722 is not in the CISA KEV catalog. Its EPSS exploit probability is 1.29%.

How severe is CVE-2026-6722?

CVE-2026-6722 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 1.29% probability of exploitation.

Which products are affected by CVE-2026-6722?

Affected products include PHP.

How do I fix CVE-2026-6722?

Upgrade affected software to a fixed version, for example PHP 8.2.31 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-6722 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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