Quick answers
- Is CVE-2025-53816 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2025-53816 being exploited in the wild.
- How severe is CVE-2025-53816?
- High severity, with a CVSS score of 7.5, published 17 July 2025.
- Which products and versions are affected?
- 7-Zip 7-Zip prior to 25.0.0.
- Is there a fix for CVE-2025-53816?
- A patch was published on 2025-07-05: Fixed in version 25.00 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2025-53816 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2025-53816?
- Check whether you run 7-Zip. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A heap-based buffer overflow exists in the NCompress::NRar5::CDecoder component of 7-Zip. The RAR5 decoder attempts to recover from corrupted items by filling them with zeroes using My_ZeroMemory. However, a miscalculation in the 'rem' value calculation (derived from attacker-controlled item sizes) allows zeroes to be written beyond the bounds of the allocated heap buffer. While the overflow is limited to writing zeroes, it can reliably cause memory corruption and application crashes. The issue is fixed in version 25.0.0.
Affected products
- 7-Zip 7-Zip prior to 25.0.0
Timeline
- 2025-04-24: other: Reported as a private issue
- 2025-07-05: patched: Fixed in version 25.00
- 2025-07-17: disclosed: Public disclosure and CVE assignment