fkie_cve-2026-41510

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.0.0 until 3.8.1, Coraza silently drops arguments after SecArgumentsLimit in internal/corazawaf/transaction.go, while internal/bodyprocessors/urlencoded.go writes ARGS_POST without enforcing the cap. The flaw is triggered when an unauthenticated attacker sends more arguments than SecArgumentsLimit or supplies bodies that expand beyond the configured argument and flattening budgets. An unauthenticated attacker can flood requests with arguments so excess values are silently omitted from ARGS, ARGS_GET, ARGS_NAMES, ARGS_GET_NAMES, ARGS_POST, or ARGS_PATH before security rules inspect them; affected urlencoded and JSON processing can also consume excessive memory. The omission can bypass WAF rules protecting the downstream application, and unbounded or amplified argument processing can cause memory consumption and service degradation. This issue is fixed in version 3.8.1.

GHSA-6r3q-mjv7-xr8m — Coraza: Silent argument drop at ArgumentLimit allows bypass of ARGS-targeted rules via parameter flooding

Affected: Go: github.com/corazawaf/coraza/v3

## Root Cause

File: `internal/corazawaf/transaction.go`, lines 770–808 (since commit 2fd87b89, PR #812, 2023-06-14)

```go func (tx *Transaction) AddGetRequestArgument(key string, value string) { if tx.checkArgumentLimit(tx.variables.argsGet) { tx.debugLogger.Warn().Msg("skipping get request argument, over limit") return } tx.variables.argsGet.Add(key, value) }

func (tx *Transaction) checkArgumentLimit(c *collections.NamedCollection) bool { return c.Len() >= tx.WAF.ArgumentLimit } ```

`AddGetRequestArgument`, `AddPostRequestArgument`, and `AddPathRequestArgument` silently `return` once the per-collection argument count reaches `WAF.ArgumentLimit` (default `1000`, see `internal/corazawaf/waf.go:346`). No error variable is set, no transaction flag is raised, and no rule can observe that a drop occurred.

Worse, `ExtractGetArguments` (`transaction.go:761`) iterates the `map[string][]string` returned by `urlutil.ParseQuery`:

```go func (tx *Transaction) ExtractGetArguments(uri string) { data := urlutil.ParseQuery(uri, '&') for k, vs := range data { // Go map iteration order is randomized for _, v := range vs { tx.AddGetRequestArgument(k, v) } } } ```

Because Go randomizes map iteration order, which of the caller-supplied arguments survive the limit is non-deterministic. An attacker can pad the URI with filler arguments; any one of them — including the malicious payload — may be the one silently d…

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fkie_cve-2026-41510

GHSA-6r3q-mjv7-xr8m — Coraza: Silent argument drop at ArgumentLimit allows bypass of ARGS-targeted rules via parameter flooding