xlnt-community xlnt XLSX File xlsx_consumer.cpp read_office_document null pointer dereference

published 2026-03-07 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-10173

cvss: 3.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits: 0; none known

A vulnerability was identified in xlnt-community xlnt up to 1.6.1. The affected element is the function xlnt::detail::xlsx_consumer::read_office_document of the file source/detail/serialization/xlsx_consumer.cpp of the component XLSX File Parser. The manipulation leads to null pointer dereference. The attack must be carried out locally. The exploit is publicly available and might be used.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 7 mo ago (2026-03-11)

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/oneafter/0128/blob/main/xl4/repro referenced PoC, tagged "exploit" by a source, unverified
github.com https://github.com/xlnt-community/xlnt/issues/140 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	4.0	4.8	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA	3.1	3.3	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA	3.0	3.3	CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA	2.0	1.7	AV:L/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR
CNA	4.0	1.9	CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA	3.1	3.3	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA	2.0	1.7	AV:L/AC:L/Au:S/C:N/I:N/A:P

Affected products

xlnt-community xlnt

Classification

Weakness

CWE-476 NULL Pointer Dereference
CWE-404 Improper Resource Shutdown or Release

References

github.com /oneafter/0128/blob/main/xl4/repro
exploit
github.com /xlnt-community/xlnt/issues/140
issue-tracking, exploit, vendor-advisory
vuldb.com /?id.349554
vdb-entry, technical-description, third-party-advisory
vuldb.com /?ctiid.349554
signature, permissions-required, vdb-entry
vuldb.com /?submit.764647
third-party-advisory, vdb-entry
github.com /xlnt-community/xlnt/
product

Sources

CVE List CVE-2026-3665
NVD CVE-2026-3665

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary