KEV Intelligence

Vulnerability report

Active exploitation observed Confirmed confidence Not in CISA KEV

CVE-2026-48611

phpBB

phpBB / phpBB · 3.3.0 to <= 3.3.16

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Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Observed in sensors
EPSS
3.9%
First observed
19 Jul 2026
Last observed
12 Aug 2026

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2026-48611 is an unauthenticated vulnerability affecting phpBB phpBB. Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to...

Is it exploited?

Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.

Who is affected?

phpBB / phpBB 3.3.0 to <= 3.3.16.

What should we do?

Patch immediately, validate internet-facing exposure, and monitor for matching requests.

Overview

phpBB

Improper authentication checks in the OAuth implementation allow account hijacking even when OAuth is not configured or enabled leading to unauthorized access in default installations.

Vendor Product Affected Status
phpBB phpBB Through 3.3.16 Affected
Published
12 Jun 2026
Exploitation Reported
19 Jul 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

php nuclei_scanner

CVE References

Exploitation evidence

Why KEV Intelligence marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

KEV Intelligence

Recorded 19 Jul 2026

Independent exploitation attestation added to the KEV Intelligence record.

Active exploitation observed

KEV Intelligence sensor

First observed 19 Jul 2026

First-party sensor telemetry confirms matching exploitation attempts.

Proof of concept available

GitHub

Recorded 13 Jun 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.

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Source Added
KEV Intelligence First 2026-07-20 07:57 UTC

Operational indicators for this CVE are listed under Detection.

Sensor telemetry

First-party evidence of exploitation activity

Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.

3

Attempts observed

3

Unique attacker IPs

3

Attacker countries

JP · NL · US

3

Sensors observed

Exploitation attempts over the last 33 days

Daily events observed by KEV Intelligence sensors

Updated 19 Aug 2026

0
1
0
0
0
0
1
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
18 Jul 25 Jul 1 Aug 8 Aug 19 Aug

First observed 19 Jul 2026 · Last observed 12 Aug 2026

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Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
1
User-Agents
3

Raw values available in Pro and Enterprise.

Virtual patch status

No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

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Attacker IP Indicators

Attacker IP indicators observed · available in Pro and Enterprise.

Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.

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Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-48611.yaml 06 Jul 2026

Risk and context

Severity, weaknesses, and research context

CVSS v3.0

9.8 Critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

3.9%

Weaknesses

Improper Authentication CWE-287

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

phpBB < 3.3.17 - Authentication Bypass

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. Observed by KEV Intelligence sensors

    Evidence-backed exploitation signal

  2. Indicators of compromise added (4)

    Indicators of compromise recorded

  3. Public PoC available

    Public proof-of-concept code published

  4. Nuclei template available

    Scanner coverage available

  5. CVE published

    Vulnerability disclosed publicly

  6. CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2026-48611

Free JSON includes basic KEV fields 
{
  "cve_id": "CVE-2026-48611",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.0386,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": true
  },
  "sensor_telemetry": { "attempts": 3, "sensors": 3 }
}

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