# CVE-2026-107834: OWASP Coraza WAF resource exhaustion in multipart processing

Source: https://junglewise.ai/threats/cve-2026-107834-coraza-resource-exhaustion-via-deferred-file-handle-accumulation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-107834 · Severity: medium · CVSS 5.3 · Published 2026-10-09

OWASP Coraza WAF is a web application firewall library that filters malicious HTTP traffic. An unauthenticated attacker can send specially crafted multipart file uploads containing many small parts to exhaust the process's file descriptor table, causing legitimate file uploads to fail and potentially preventing the entire application from opening files or network connections.

Technologies: [github.com/corazawaf/coraza (Go)](https://junglewise.ai/threats/technologies/github-com-corazawaf-coraza), [github.com/corazawaf/coraza/v2 (Go)](https://junglewise.ai/threats/technologies/github-com-corazawaf-coraza-v2), [github.com/corazawaf/coraza/v3 (Go)](https://junglewise.ai/threats/technologies/github-com-corazawaf-coraza-v3), [OWASP Coraza WAF](https://junglewise.ai/threats/technologies/owasp-coraza-waf). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [OWASP](https://junglewise.ai/threats/vendors/owasp).

## Quick answers

**Is CVE-2026-107834 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-107834 being exploited in the wild.

**How severe is CVE-2026-107834?** Medium severity, with a CVSS score of 5.3, published 9 October 2026.

**Which products and versions are affected?** github.com/corazawaf/coraza (Go) SEMVER:introduced=0; github.com/corazawaf/coraza/v2 (Go) SEMVER:introduced=0; github.com/corazawaf/coraza/v3 (Go) SEMVER:introduced=3.0.0,fixed=3.8.0; OWASP Coraza WAF 3.0.0 to 3.7.0.

**Is there a fix for CVE-2026-107834?** Yes. github.com/corazawaf/coraza/v3 (Go): upgrade to 3.8.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-107834 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-107834?** Check whether you run github.com/corazawaf/coraza (Go), github.com/corazawaf/coraza/v2 (Go), github.com/corazawaf/coraza/v3 (Go) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/corazawaf/coraza/v3 (Go): upgrade to 3.8.0 or later

  ```sh
  go get github.com/corazawaf/coraza/v3@v3.8.0
  ```


## Technical details

The vulnerability exists in the multipart body processor where file descriptor cleanup is deferred until the entire request completes, rather than being released immediately after processing each part. An attacker can craft a multipart POST request with many minimal file parts that collectively stay under size limits but exhaust available file descriptors, triggering os.CreateTemp failures and causing MULTIPART_STRICT_ERROR responses. The fix moves temp file closure from deferred to immediate, executed right after io.Copy completes for each part.

## Affected products

- OWASP Coraza WAF 3.0.0 to 3.7.0

## Identifiers

- CVE-2026-107834
- GHSA-rp9v-7xv3-r6g3
- GO-2026-6697

## Timeline

- 2026-10-09: disclosed
- 2026-09-30: patched

## References

- [https://github.com/corazawaf/coraza/commit/1bc39036e99c88e7de60cf8e6bb55ee4c311223c](https://github.com/corazawaf/coraza/commit/1bc39036e99c88e7de60cf8e6bb55ee4c311223c)
- [https://github.com/corazawaf/coraza/releases/tag/v3.8.0](https://github.com/corazawaf/coraza/releases/tag/v3.8.0)

## Related threats

- [Coraza multipart filename rule bypass via RFC 5987 charset handling](https://junglewise.ai/threats/cve-2026-114101-coraza-before-3-8-1-extracts-multipart-upload-filenames-with-go)
- [Coraza request body inspection bypass in Content-Type parsing](https://junglewise.ai/threats/cve-2026-114100-coraza-from-3-0-4-before-3-8-1-contains-a-request-body)
- [Coraza JSON body processor key collision WAF bypass](https://junglewise.ai/threats/cve-2026-114099-coraza-from-3-0-0-before-3-8-1-has-a-json-body-processor-that)
- [Coraza multipart strict validation bypass via truncated body](https://junglewise.ai/threats/cve-2026-41508-coraza-truncated-multipart-body-bypasses-multipart-strict-error)
- [Coraza CRLF injection in Native audit-log format](https://junglewise.ai/threats/cve-2026-41504-coraza-native-audit-log-format-allows-crlf-injection-and-log)