High severity · published Oct 7, 2026
CVE-2026-107215
Excelize: extractPart allocates attacker-controlled, unbounded and negative-sized buffers from CFB directory entries: remote panic / OOM DoS
7.5
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 15% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EX
excelize · qax-os
>= 2.3.1, <= 2.11.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-107215
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-107215
x_refsource_CONFIRM
https://github.com/qax-os/excelize/security/advisories/GHSA-x2q3-8cjh-766f
x_refsource_MISC
https://github.com/qax-os/excelize/pull/2396
x_refsource_MISC
https://github.com/qax-os/excelize/commit/5f636f9dcde55911f14290060b017f0cc88cd694
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