CVE
Defender Security auth bypass via IP spoofing in smart IP detection
- Exploited
- No known exploitation
- Fix
- Fixed in 6.4.1
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 6.4.1.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.19% · 9th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 25/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: yes
- Technical impact: partial
Summary
The Defender Security WordPress plugin does not verify that the client IP address it uses for firewall and lockout decisions comes from a trusted source, so unauthenticated attackers can spoof their IP address. This lets them evade IP-based protections such as login lockout and IP banning, impersonate an allowlisted address, and pollute the plugin's activity logs.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
The Defender Security WordPress plugin before 6.4.1 does not verify that the client IP address it derives for its firewall and lockout decisions actually originates from a trusted source, trusting a user-supplied value by default, allowing unauthenticated attackers to spoof their IP address and evade IP-based protections such as login lockout and IP banning, impersonate an allowlisted address, and poison the Defender Security WordPress plugin before 6.4.1's activity logs.
cve.now Index
- Exploitation0/40No signal
- Exposure20/25No login or user action needed per the CVSS vector, CISA rates it automatable · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity5.3/10CVSS 5.3
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
- Would score about 30 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 6.4.1.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-119039 (Defender Security 4.9.0 - 6.4.0 - Unauthenticated IP Address Spoofing via Smart IP Detection), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-119039 (entry last updated 2026-11-12):
Affected:
- Unknown Defender Security: from 4.9.0, fixed in 6.4.1
Fixed versions: 6.4.1.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-119039 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-119039 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- the references on https://cve.now/CVE-2026-119039
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-119039
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-119039"}.Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- Unknown Defender Security
From 4.9.0 · fixed in 6.4.1
Evidence 3
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Public exploit code · 1
Establishes: Public exploit code exists (Exploit-DB, Metasploit, Nuclei and GitHub).
- Exploit
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-119039
Is CVE-2026-119039 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-119039?
Defender Security: from 4.9.0 before 6.4.1.Source: cve.now feed data
How do I fix CVE-2026-119039?
Upgrade to a fixed version: 6.4.1.Source: cve.now feed data