Summary
Excelize: Unbounded spinCount in agile decryption burns CPU during OpenFile
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 it either.
v2.5.0 spinCount=10000000 5.307s
v2.9.1 spinCount=10000000 5.444s
v2.11.0 spinCount=10000000 7.529s
v2.11.0 spinCount=100000000 58.654s
The loop arrived with crypt.go in v2.3.1 and is unchanged through v2.11.0.
Excel and LibreOffice write spinCount 100000, which costs 61ms here, so a ceiling well above the legitimate value would cost real files nothing.
This is availability only, and it is not a vulnerability for a program that only opens files its own operator produced.
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2026-107219 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.11.1-0.20260906004932-2badfcd5841d); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-107219? CVE-2026-107219 is a high-severity uncontrolled resource consumption vulnerability in github.com/xuri/excelize/v2 (go), affecting versions >= 2.3.1, < 2.11.1-0.20260906004932-2badfcd5841d. It is fixed in 2.11.1-0.20260906004932-2badfcd5841d. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2026-107219? CVE-2026-107219 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/xuri/excelize/v2 are affected by CVE-2026-107219? github.com/xuri/excelize/v2 (go) versions >= 2.3.1, < 2.11.1-0.20260906004932-2badfcd5841d is affected.
- Is there a fix for CVE-2026-107219? Yes. CVE-2026-107219 is fixed in 2.11.1-0.20260906004932-2badfcd5841d. Upgrade to this version or later.
- Is CVE-2026-107219 exploitable, and should I be worried? Whether CVE-2026-107219 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-107219 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-107219? Upgrade
github.com/xuri/excelize/v2to 2.11.1-0.20260906004932-2badfcd5841d or later.