What’s Vulnerable › Vulnerabilities

CVE-2026-107215: Excelize: extractPart allocates attacker-controlled, unbounded and negative-sized buffers from CFB directory entries: remote panic / OOM DoS

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-10-07 · updated 2026-10-13
• Weakness: CWE-789

Description

Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.3.1 to 2.11.0, extractPart allocates a byte slice directly from an attacker-controlled CFB directory-entry size before validating the sector chain or size domain. extractPart trusts the CFB directory entry streamSize for EncryptionInfo and EncryptedPackage allocations before validating the stream. When a crafted OLE compound file declares a negative or extremely large EncryptionInfo or EncryptedPackage stream size, the declared size reaches make with a negative length or forces a multi-gigabyte allocation, allowing an attacker to panic or exhaust process memory. No fixed version is available as of this review.

Affected products

• qax-os excelize: from 2.3.1 through 2.11.0

References

• https://github.com/qax-os/excelize/commit/5f636f9dcde55911f14290060b017f0cc88cd694
• https://github.com/qax-os/excelize/pull/2396
• https://github.com/qax-os/excelize/security/advisories/GHSA-x2q3-8cjh-766f
• https://github.com/qax-os/excelize/security/advisories/GHSA-x2q3-8cjh-766f

Get alerted when CVE-2026-107215 or the next vulnerability affects your stack