CVE-2026-107215: excelize — Exploit & Fix

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0024

Probability of exploitation

0.15%

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-789 CWE-789

Affected Products

Vendor	Product	Versions
excelize	excelize	2.3.1 — 2.11.0

References

Advisories & Patches

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

Exploits

https://github.com/qax-os/excelize/security/advisories/GHSA-x2q3-8cjh-766f https://github.com/qax-os/excelize/security/advisories/GHSA-x2q3-8cjh-766f

Frequently Asked Questions

What is CVE-2026-107215? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-107215? +

CVE-2026-107215 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0024, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-107215? +

CVE-2026-107215 affects products from excelize, specifically: excelize. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-107215? +

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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