CVE-2026-6722

CRITICALCVSS 9.5/10EPSS 0.51%

Last modified

CVE-2026-6722 is a critical-severity vulnerability rated 9.5/10 on the CVSS scale. 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. EPSS estimates a 0.51% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
9.8/10

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

CVSS 4.0
9.5/10

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:Red

EPSS Probability
0.51%

39.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
PhpPhp>= 8.2.0, < 8.2.31
PhpPhp>= 8.3.0, < 8.3.31
PhpPhp>= 8.4.0, < 8.4.21
PhpPhp>= 8.5.0, < 8.5.6

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-6722?
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.
How severe is CVE-2026-6722?
CVE-2026-6722 has a CVSS score of 9.5/10 (CRITICAL severity). The EPSS model estimates a 0.51% probability of exploitation in the next 30 days.
How do I fix CVE-2026-6722?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-6722?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST