CVE-2026-42444

LOW
Published May 12, 2026 Modified May 18, 2026 CWE-770

Description

NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a denial-of-service vulnerability exists in the littlefs filesystem image parser in NanaZip. The handler's Open method reads BlockCount directly from the attacker-controlled superblock without any validation against the actual file size or any upper-bound ceiling, then iterates BlockCount times, allocating a file-path entry per iteration. A crafted 44-byte littlefs image with BlockCount = 0xFFFFFFFF causes ~4 billion heap allocations, exhausting available memory. This vulnerability is fixed in 6.0.1698.0.

CVSS v3.1 Score

3.3
LOW
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS — Exploit Prediction

0.0001
Probability of exploitation
0.03%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-770 CWE-770

Affected Products

Vendor Product
m2team nanazip

References

Frequently Asked Questions

What is CVE-2026-42444? +
NanaZip is an open source file archive. From 5.0.1252.0 to before 6.0.1698.0, a denial-of-service vulnerability exists in the littlefs filesystem image parser in NanaZip. The handler's Open method reads BlockCount directly from the attacker-controlled superblock without any validation against the actual file size or any upper-bound ceiling, then iterates BlockCount times, allocating a file-path entry per iteration. A crafted 44-byte littlefs image with BlockCount = 0xFFFFFFFF causes ~4 billion heap allocations, exhausting available memory. This vulnerability is fixed in 6.0.1698.0. It has a CVSS v3.1 base score of 3.3 (LOW).
How severe is CVE-2026-42444? +
CVE-2026-42444 has a CVSS v3.1 score of 3.3 out of 10, rated LOW. This is a low-severity vulnerability with limited impact. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-42444? +
CVE-2026-42444 affects products from m2team, specifically: nanazip. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-42444? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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