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VulnerabilityPublished

CVE-2026-104774: corazawaf coraza · Encoding Error

Affects corazawaf corazaSource CVE Database V5

0

Public exploit available · CVSS 5.8 Medium : upgrade to 3.8.0 as a priority.

Data as of 26 Oct 2026, 12:29 UTC

CVSS 3.1 base score
5.8Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
Proof of concept is public or traded
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-13.

Patch
Available – fixed in 3.8.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

  1. Disclosed: evidence found.

    CVE published 12 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: evidence found.

    CISA SSVC: proof of concept public

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

Timeline

  1. CVE ID reserved

    by GitHub, Inc.

    , 10 days before disclosure

  2. CVE published

    on cve.org

    , t = 0

  3. CISA SSVC assessment

    proof of concept public

    , 20 hours after disclosure

  4. In Threat Radar

    record ingested

    , 14 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade corazawaf coraza to 3.8.0.

Affected software

ProductAffectedFixed in
corazawafcorazaAffected
  • >=3.0.0 <3.8.0
Fixed in
  • 3.8.0

Description

OWASP Coraza WAF is a golang modsecurity compatible web application firewall library. From 3.0.0 until 3.8.0, the t:jsDecode transformation in internal/transformations/js_decode.go:64-70 includes the backslash in the octal buffer, causing ParseInt to fail and return a null byte. The flaw is triggered when a rule relies on t:jsDecode and the request contains JavaScript octal escape sequences. An unauthenticated attacker can encode attack syntax with JavaScript octal escapes so the backend decodes the intended bytes while Coraza rules using t:jsDecode inspect corrupted null-byte output. The mismatch can bypass WAF rules and expose the protected application to attacks such as cross-site scripting or SQL injection. This issue is fixed in version 3.8.0.

References

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