cve.bz

CVE-2026-128344 ExcelJS through 4.4.0 Memory Exhaustion via Oversized Image Anchor Column

8.7 highEPSS 0.6%

High (8.7) in exceljs exceljs. EPSS 0.6% estimated probability of exploitation activity in the next 30 days.

On this page
ExcelJS through 4.4.0 contains a memory exhaustion vulnerability that allows attackers to crash applications by supplying a workbook with an unbounded image anchor column in the drawing part. Attackers can set an anchor column such as 300000000 in xl/drawings/drawing1.xml so reading getImages() anchor positions makes Worksheet.getColumn allocate millions of Column objects and abort with a heap out-of-memory error.

Severity

CVSS 4.0

8.7 high
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.6% estimated probability of exploitation activity in the next 30 days; 51st percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
CISA's assessment (SSVC)
Exploitation: PoC · Automatable: yes · Technical impact: partial, assessed 2026-11-13. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
CWE
CWE-770 Allocation of Resources Without Limits or Throttling
Published
Modified
Assigned by
VulnCheck (CNA)
NVD analysis
Awaiting analysis
Record from
the NVD, synced

Ask an AI about this CVE

ChatGPTClaudeGoogle AI Mode

Show the promptExplain CVE-2026-128344 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-128344?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-128344?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-128344 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.

Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.

Badge for a README or a site

CVE-2026-128344

An image that stays current: it is drawn from the data each time it is fetched (a host that proxies images, as GitHub does, may show its copy for a while). Markdown:

[![CVE-2026-128344](https://cve.bz/cve/badge/CVE-2026-128344.svg)](https://cve.bz/cve/CVE-2026-128344)

HTML:

<a href="https://cve.bz/cve/CVE-2026-128344"><img src="https://cve.bz/cve/badge/CVE-2026-128344.svg" alt="CVE-2026-128344"></a>

Affected

Versions

From the CNA's record in the CVE List.

ProductAffected
exceljsthrough 4.4.0

Attack patterns (CAPEC)

The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-770 (20).

References

Check your stackJSON