High · CVSS 7.5CVE-2026-107215

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

Answer in brief

CVE-2026-107215 records a High severity (CVSS 7.5) vulnerability in Excelize: extractPart allocates attacker-controlled, unbounded and negative-sized buffers from CFB directory entries: remote panic / OOM DoS. The current sources do not mark it as known exploited. The current feed maps qax-os/excelize (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 7, 2026Updated Oct 7, 2026Source checked Oct 7, 2026First seen by HOL Oct 7, 2026Material review Oct 7, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps qax-os/excelize (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
qax-os/excelizegeneric	>=2.3.1 <=2.11.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for qax-os/excelize.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 7, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 7, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.