4

CVE-2026-107835: OWASP Coraza WAF: Cookie Parser Confusion

Awaiting analysis
AliasesGHSA-g4qm-m288-5cp9GO-2026-6694
Published 09-10-2026Last modified 09-10-2026

Vulnerability summary

CVE-2026-107835 is a medium (CVSS 4.0) Interpretation Conflict vulnerability in corazawaf coraza. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 22.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.0/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 09-10-2026
    PublishedVulnerability first disclosed.
  2. 09-10-2026
    Last modifiedVulnerability information updated.

Description

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. Prior to 3.8.1, internal/cookies.ParseCookies in internal/cookies/cookies.go handles boundary ASCII control characters and control-only or empty cookie names differently from several backend cookie parsers. An unauthenticated attacker can craft a Cookie header so Coraza indexes or drops a cookie under a different name or value from the backend application, causing rules targeting REQUEST_COOKIES or REQUEST_COOKIES_NAMES to miss application-visible attacker data. Exploitation depends on the backend parser and affected rule scope, and interior control characters with inconsistent backend behavior are outside this advisory's remediation. This issue is fixed in version 3.8.1.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

10-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Github.com/corazawaf/coraza2 products
  • v2All versions (No fix recorded)
  • v3< 3.8.1
Corazawaf1 product
Github.com/corazawaf1 product
  • corazaAll versions (No fix recorded)

3 vendors · 4 products

References

5 links