CVE-2023-38853Public exploitNetwork attack vector

Application crash via undersized XLS STYLE record

Published Aug 15, 2023 · Updated Oct 8, 2024

Heap-buffer over-read in libxls 1.6.2 allows remote attackers to crash applications that parse a crafted XLS STYLE record. xls_parseWorkBook reads a two-byte style index before confirming that the record buffer contains two bytes, and it passes incorrect lengths to string decoders. Exploitation requires an application to open attacker-supplied XLS input; public testing establishes an out-of-bounds read and process abort, not code execution.

CVSS severity6.5
Medium
EPSS probability0.87%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-buffer over-read in libxls 1.6.2 allows remote attackers to crash applications that parse a crafted XLS STYLE record. xls_parseWorkBook reads a two-byte style index before confirming that the record buffer contains two bytes, and it passes incorrect lengths to string decoders. Exploitation requires an application to open attacker-supplied XLS input; public testing establishes an out-of-bounds read and process abort, not code execution.

The record

CVE
CVE-2023-38853
Published
Aug 15, 2023
Updated
Oct 8, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125, CWE-787, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 8, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5CanonicalCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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