CVE-2026-107220 — Excelize: Panic in cellInRange on a worksheet with an empty mergeCell ref
Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.7.1 to 2.11.0, mergeCellsParser leaves the cached rectangle empty for an empty mergeCell ref and then passes that empty slice to cellInRange without a length check. GetCellValue reaches mergeCellsParser, which passes an empty rectangle derived from the mergeCell ref attribute into cellInRange. When a crafted worksheet contains an empty mergeCell ref and a non-streaming cell API reads the worksheet, cellInRange indexes four positions in an empty slice, allowing an attacker to panic on the first affected cell operation. No fixed version is available as of this review.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
- Technical severity (medium)+3
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Excelize Excelize, Qax-os Excelize).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Exploitation requires user interaction: tighten email/web filtering and warn affected users.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.5 | CVSS 3.1 | Medium | 2.8 | 3.6 | security-advisories@github.com via NIST National Vulnerability Database |
| 6.5 | CVSS 3.1 | Medium | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.25%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · qax-os/excelize
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 6.5
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-107225 Excelize: GetStyle panics on a negative fillId, borderId or fontId in styles.xml 8d
- Medium CVE-2026-107224 Excelize: A Zip64 uncompressed-size of 2^63 panics OpenFile/OpenReader 8d
- Medium CVE-2026-107218 Excelize: RIGHT() on supplementary-plane text slices with a negative index and panics 8d
- Medium CVE-2026-107222 Excelize: GetConditionalFormats indexes conditional-formatting rule sub-elements with no length or nil check 8d
- High CVE-2026-107219 Excelize: Unbounded spinCount in agile decryption burns CPU during OpenFile 8d
- Medium CVE-2026-107221 Excelize: a row whose earlier cell has a higher column reference than its last cell panics index out of range on almost every worksheet read API 8d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-107220 is "Excelize: Panic in cellInRange on a worksheet with an empty mergeCell ref", rated Medium. It affects Excelize (Excelize); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. EPSS 0.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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