Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-41508 medium CVSS 5.8

Vulnerability in github.com/corazawaf/coraza/v3 (CVE-2026-41508)

Summary

Vulnerability in github.com/corazawaf/coraza/v3 (CVE-2026-41508). Risk of unauthorized operations or information disclosure. Exploitable via io.ErrUnexpectedEOF. Mitigation: upgrade to 3.8.0 or later.

Original description

The description as published by the source.

Root Cause

File: internal/bodyprocessors/multipart.go (since commit 3347961b, PR #1453 "feat: ignore unexpected EOF in MIME multipart request body processor", merged 2026-03-06, first shipped in v3.4.0).

The multipart body processor treats io.ErrUnexpectedEOF as a benign condition. Three sites are affected; all mishandle the error the same way.

File branch, filesystem-backed (lines 71–77)

sz, err := io.Copy(temp, p)
if err != nil {
    if !errors.Is(err, io.ErrUnexpectedEOF) {
        v.MultipartStrictError().(*collections.Single).Set("1")
        return err
    }
    seenUnexpectedEOF = true     // <-- flag never set for UnexpectedEOF
}

File branch, TinyGo path (lines 82–88)

sz, err := io.Copy(io.Discard, p)
if err != nil {
    if !errors.Is(err, io.ErrUnexpectedEOF) {
        v.MultipartStrictError().(*collections.Single).Set("1")
        return err
    }
    seenUnexpectedEOF = true     // <-- same gap
}

Field branch (lines 102–113)

data, err := io.ReadAll(p)
if err != nil {
    if !errors.Is(err, io.ErrUnexpectedEOF) {
        v.MultipartStrictError().(*collections.Single).Set("1")
        return err
    }
}
...
if errors.Is(err, io.ErrUnexpectedEOF) {
    break                         // <-- exits loop with no flag set
}

The function then returns nil at line 116 for any body that ended prematurely. Consequences:

  1. MULTIPART_STRICT_ERROR stays at its initial value 0.
  2. REQBODY_ERROR is not propagat…

Source: GitHub Security Advisories (Global) 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-2026-41508 has been found in github.com/corazawaf/coraza/v3.
Attackers can target a specific entry point like io.ErrUnexpectedEOF over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.8/10.
What to do: upgrade github.com/corazawaf/coraza/v3 to 3.8.0 or later.
If unsure, ask your IT team or search "github.com/corazawaf/coraza/v3 CVE-2026-41508" on the vendor's site.

CVE-2026-41508 (github.com/corazawaf/coraza/v3) — CWE-693 / CVSS v3 5.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: io.ErrUnexpectedEOF / nil / MULTIPART_STRICT_ERROR / REQBODY_ERROR
Patched: 3.8.0 — 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.

❓ What is the problem

A vulnerability (CWE-693) exists in github.com/corazawaf/coraza/v3. Attackers reach the vulnerable code path via io.ErrUnexpectedEOF without authentication.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/corazawaf/coraza/v3. Attack surface: io.ErrUnexpectedEOF / nil / MULTIPART_STRICT_ERROR / REQBODY_ERROR.

🔥 Severity

Severity: Medium (CVSS 5.8/10). Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 3.8.0.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/corazawaf/coraza/v3' . 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

  1. 1
    Identify exposure identify 
    grep -r 'github.com/corazawaf/coraza/v3' . | 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/corazawaf/coraza/v3 を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply patch patch 
    Upgrade github.com/corazawaf/coraza/v3 to 3.8.0

    ステージング環境で 3.8.0 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。

  3. 3
    Post-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

go github.com/corazawaf/coraza/v3
[{"type":"SEMVER","events":[{"introduced":"3.4.0"},{"fixed":"3.8.0"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details