How severe is CVE-2026-71558?

CVE-2026-71558 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-71558 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-71558?

CVE-2026-71558 affects Apache Fory. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-71558?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-71558 published?

CVE-2026-71558 was published on 2026-08-07 and last updated on 2026-08-08.

CVE-2026-71558

CVE-2026-71558 is a critical-severity vulnerability in Apache Fory with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-843.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-843
Affected product: Apache Fory
Published: 2026-08-07
Last modified: 2026-08-08

Description

Heap type confusion vulnerability in Apache Fory C++ deserialization. This issue affects Apache Fory C++ versions from 0.14.0 before 1.5.0. A crafted input payload can bypass type compatibility checks during polymorphic smart-pointer deserialization, causing an object of an incompatible type to be treated as the declared base type. This may result in undefined behavior and potentially lead to denial of service or arbitrary code execution. Users are recommended to upgrade to Apache Fory 1.5.0, which fixes this issue. Applications not using Apache Fory C++ polymorphic smart-pointer deserialization are not affected.

Frequently asked questions

What is CVE-2026-71558?: Heap type confusion vulnerability in Apache Fory C++ deserialization. This issue affects Apache Fory C++ versions from 0.14.0 before 1.5.0. A crafted input payload can bypass type compatibility checks during polymorphic smart-pointer deserialization, causing an object of an incompatible type to be treated as the declared base type. This may result in undefined behavior and potentially lead to denial of service or arbitrary code execution. Users are recommended to upgrade to Apache Fory 1.5.0, which fixes this issue. Applications not using Apache Fory C++ polymorphic smart-pointer deserialization are not affected.
How severe is CVE-2026-71558?: CVE-2026-71558 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-71558 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-71558?: CVE-2026-71558 affects Apache Fory. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-71558?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-71558 published?: CVE-2026-71558 was published on 2026-08-07 and last updated on 2026-08-08.

References

Affected products (1)

cpe:2.3:a:apache:fory:*:*:*:*:*:*:*:*

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