November 14, 2026

CVE Watchtower

CVE-2026-104259

NVDCVSS scored by security-advisories@github.com

Vulnerability Summary

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. Prior to 2.9.15 and 3.0.17, msre_fn_removeComments_execute in apache2/re_tfns.c and inplace() in src/actions/transformations/remove_comments.cc implement t:removeComments by copying the character immediately after a comment terminator without re-evaluating it. Adjacent comments can therefore leave a later comment in the transformed value, allowing inline-comment obfuscation to bypass rules that depend on comment stripping. When a comment terminator is the final content, the same copy reads one byte beyond the input buffer. This issue is fixed in versions 2.9.15 and 3.0.17.
Severity Level
MEDIUM(5.4)
Published Date
Nov 9, 2026
Last Modified
Nov 12, 2026
Exploitation Status
No confirmed exploitation yet
CVE Record Status
Published
EPSS Score (30-Day)
0.22%Probability
Root Weakness (CWE)
CWE-670 β†—
See the MITRE CWE entry for the full definition of this weakness.
CVSS v3.1 Base Metrics — Score 5.4 (MEDIUM)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

Affected & Patched Versions

Affected Versions
Not provided by NVD for this CVE.
Patched Versions
No patched version published yet
Until a fix ships, reduce exposure:
  • Restrict access to the affected service or interface to trusted networks.
  • Disable the affected feature if you do not need it.
  • Watch the vendor advisory for a firmware or software update.

What to do

Fix it during your normal patch cycle. No exploitation is confirmed yet.

  1. Check whether you run the affected product and which version.
  2. No patched version is listed yet. Limit access to the affected service to trusted networks, and disable the feature if you can.
  3. Subscribe to the vendor advisory so you learn when a fix ships.

Timeline

  • Nov 9, 2026Published
  • Nov 12, 2026Record last modified

Score, severity and exploitation changes are tracked from the day Watchtower started logging them.

Get alerts for CVEs like this oneYou are reading CVE-2026-104259. Get an email when KEV listings, exploits or new CVEs match your stack.
Set up CVE alerts

External References

Data last checked: Nov 9, 2026 23:00 UTC