Vulnerability in github.com/xuri/excelize/v2 (CVE-2026-107219)
Summary
Vulnerability in github.com/xuri/excelize/v2 (CVE-2026-107219). Risk of unauthorized operations or information disclosure. Exploitable via openReaderAt. Mitigation: upgrade to 2.11.1-0.20260906004932-2badfcd5841d or later.
Original description
The description as published by the source.
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…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-107219 has been found in github.com/xuri/excelize/v2.
Attackers can target a specific entry point like openReaderAt over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260906004932-2badfcd5841d or later.
If unsure, ask your IT team or search "github.com/xuri/excelize/v2 CVE-2026-107219" on the vendor's site.
CVE-2026-107219 (github.com/xuri/excelize/v2) — CWE-400 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: openReaderAt / agileDecrypt / convertPasswdToKey / spinCount
Patched: 2.11.1-0.20260906004932-2badfcd5841d — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-400) exists in github.com/xuri/excelize/v2. Attackers reach the vulnerable code path via openReaderAt without authentication.
Check the vendor advisory for the affected versions of github.com/xuri/excelize/v2. Attack surface: openReaderAt / agileDecrypt / convertPasswdToKey / spinCount.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 2.11.1-0.20260906004932-2badfcd5841d.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/xuri/excelize/v2' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'github.com/xuri/excelize/v2' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/xuri/excelize/v2を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/xuri/excelize/v2 to 2.11.1-0.20260906004932-2badfcd5841dステージング環境で 2.11.1-0.20260906004932-2badfcd5841d に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- exploit security-advisories@github.com
- patch security-advisories@github.com
- patch security-advisories@github.com
- web github.com