CVE-2026-59162
Fix: qax-os/excelize@93f0b3cCVE-2026-59162 is a CWE-248 vulnerability in github.com/xuri/excelize/v2. O3 Security confirms whether CVE-2026-59162 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Excelize: Negative shared-string index causes panic in GetCellValue and GetRows
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-59162.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/xuri/excelize/v2🐹github.com/xuri/excelizeReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. Prior to 2.11.0, Excelize parses shared-string cell values with strconv.Atoi and checks only the upper bound before indexing the shared string slice, allowing an XLSX file containing a shared-string cell with -1 to trigger sharedStrings[-1] and panic when read through GetCellValue or GetRows. This issue is fixed in version 2.11.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/xuri/excelize/v2 | all versions | 2.11.0 |
| 🐹Go | github.com/xuri/excelize | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/xuri/excelize/v2. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/xuri/excelize/v2 to 2.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-59162 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-59162 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-59162. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-59162 in your dependencies?
O3 detects CVE-2026-59162 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.