Is CVE-2026-29199 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-29199 being exploited in the wild.

How severe is CVE-2026-29199?

High severity, with a CVSS score of 8.1, published 4 May 2026.

Which products and versions are affected?

phpbb/phpbb (Packagist) ECOSYSTEM:introduced=3.0.0,fixed=3.3.16.

Is there a fix for CVE-2026-29199?

Yes. phpbb/phpbb (Packagist): upgrade to 3.3.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-29199 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-29199?

Check whether you run phpbb/phpbb (Packagist) or Phpbb at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-29199: phpBB Host Header Injection in password reset mechanism

CVE-2026-29199 · Severity: high · CVSS 8.1 · Published 2026-05-04

phpBB, a popular open-source forum software, is vulnerable to a flaw that allows attackers to manipulate password reset emails. By tricking the system into using a malicious web address, an attacker can send a legitimate-looking password reset link to a user that actually directs them to a site controlled by the attacker. If a user clicks this link, the attacker can capture their credentials and take over their account.

Technologies: phpbb/phpbb (Packagist), Phpbb. Vendors: Packagist, Phpbb.

Quick answers

Is CVE-2026-29199 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-29199 being exploited in the wild.
How severe is CVE-2026-29199?: High severity, with a CVSS score of 8.1, published 4 May 2026.
Which products and versions are affected?: phpbb/phpbb (Packagist) ECOSYSTEM:introduced=3.0.0,fixed=3.3.16.
Is there a fix for CVE-2026-29199?: Yes. phpbb/phpbb (Packagist): upgrade to 3.3.16 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-29199 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-29199?: Check whether you run phpbb/phpbb (Packagist) or Phpbb at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

phpbb/phpbb (Packagist): upgrade to 3.3.16 or later
```
composer require phpbb/phpbb:^3.3.16
```

Technical details

phpBB before 3.3.16 and version 4.0.0-a1 are vulnerable to Host Header Injection (CWE-640). When the 'force_server_vars' configuration is disabled, the application may use the HTTP Host header provided by the client to generate absolute URLs for password reset emails. An attacker can provide a malicious Host header during a password reset request; if the web server does not validate this header, the resulting email will contain a reset link pointing to an attacker-controlled domain. This allows the attacker to intercept the reset token when the victim clicks the link, leading to account takeover. The issue is patched in versions 3.3.16 and 4.0.0-a2.

Affected products

phpBB phpBB >= 3.0.0, < 3.3.16; 4.0.0-a1

Identifiers

CVE-2026-29199
GHSA-7gm6-w7mx-58cr

Timeline

2026-04-27: patched: Patch released in version 4.0.0-a2
2026-05-04: disclosed
2026-05-04: advisory

References

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