Excelize: Unbounded spinCount in agile decryption burns CPU during OpenFile

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2026-107219: 0.36% estimated exploitation activity in the next 30 days; percentile 30.15 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Opening a file whose first eight bytes are the OLE magic number sends excelize down the decryption path whether or not the caller set a password, or supports encrypted workbooks at all. openReaderAt (excelize.go:198-215) branches on the header alone, and agileDecrypt calls convertPasswdToKey before the verifier hash is checked, so the key-derivation loop runs spinCount times regardless. spinCount (crypt.go:98) is a plain int filled by a bare xml.Unmarshal of the file's own EncryptionInfo stream. Nothing bounds it. A 3072-byte file with spinCount 100000000 makes OpenFile take 58.65s on v2.11.0 with default options, then return zip: not a valid zip file. It is linear at about 0.6 microseconds per iteration and the attacker picks the number, so 1e9 is roughly ten minutes. Nothing on the path takes a context.Context, so the caller cannot cancel it; in an HTTP handler the write timeout returns a response while the goroutine keeps spinning. Memory stays flat at 24 MB, so nothing reclaims…

Published by the source

7 Oct 2026, 20:23 UTC

Last modified by the source

7 Oct 2026, 20:30 UTC

Source last checked

26 Oct 2026, 15:29 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-jrfj-fhj2-jjvm

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-jrfj-fhj2-jjvm

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# Patch Next advisory brief: CVE-2026-107219

Advisory: Excelize: Unbounded spinCount in agile decryption burns CPU during OpenFile
IDs: CVE-2026-107219, GHSA-jrfj-fhj2-jjvm
Record: https://patchnext.com/advisories/cve-2026-107219 (revision 2, source checked 26 Oct 2026, 15:29 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/xuri/excelize/v2 2.11.1-0.20260906004932-2badfcd5841d. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/xuri/excelize/v2: affected >= 2.3.1, < 2.11.1-0.20260906004932-2badfcd5841d; fixed in 2.11.1-0.20260906004932-2badfcd5841d

## Suggested inspection (read-only)
- Go github.com/xuri/excelize/v2: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/xuri/excelize/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-jrfj-fhj2-jjvm (OSV record GHSA-jrfj-fhj2-jjvm lists affected ranges: Go github.com/xuri/excelize/v2 >=2.3.1 <2.11.1-0.20260906004932-2badfcd5841d (fixed))
- Verified: https://github.com/advisories/GHSA-jrfj-fhj2-jjvm (GitHub-reviewed advisory GHSA-jrfj-fhj2-jjvm lists affected ranges: Go github.com/xuri/excelize/v2 >=2.3.1 <2.11.1-0.20260906004932-2badfcd5841d)

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