CVE-2025-62821

CVE-2025-62821 is a critical-severity vulnerability in Microsoft Heif Image Extension with a CVSS 3.x base score of 9.1. 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-125.

Key facts

Description

Microsoft HEIF Image Extensions 1.2.22.0 has an out-of-bounds read because CHEIFItemInfoEntry_GetDataSize can return success while leaving the reported data size as 0. This causes a caller to make a 1-byte allocation. Later, CopyPixels computes copy_size = stride * abs(roi_height) but does not check the source buffer length before a memmove call.

Frequently asked questions

What is CVE-2025-62821?
Microsoft HEIF Image Extensions 1.2.22.0 has an out-of-bounds read because CHEIFItemInfoEntry_GetDataSize can return success while leaving the reported data size as 0. This causes a caller to make a 1-byte allocation. Later, CopyPixels computes copy_size = stride * abs(roi_height) but does not check the source buffer length before a memmove call.
How severe is CVE-2025-62821?
CVE-2025-62821 has a CVSS 3.x base score of 9.1, 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 none, and availability high.
Is CVE-2025-62821 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-62821?
CVE-2025-62821 affects Microsoft Heif Image Extension. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-62821?
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.
Does CVE-2025-62821 have an EU (EUVD) identifier?
Yes. CVE-2025-62821 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-210287.
When was CVE-2025-62821 published?
CVE-2025-62821 was published on 2026-06-19 and last updated on 2026-06-30.

References

Affected products (1)

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