SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-29199

phpBB before 3.3.16 is vulnerable to Host Header Injection that can lead to password rest link poisoning.

HIGH 8.1EPSS 0.25%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.25%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

phpBB before 3.3.16 is vulnerable to Host Header Injection that can lead to password rest link poisoning. When force_server_vars is disabled, the servers hostname may be extracted from the HTTP Host header which is used to generate the password reset link URL. An attacker who can manipulate the Host header (e.g. through misconfigured host setup or missing header validation by the webserver) can cause password reset emails to contain a link pointing to an attacker-controlled domain, potentially leading to account takeover.

CVSS 3.1
8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS
0.25% probability · 16th percentile
CISA KEV
Not listed
Weakness
CWE-640
Affected
phpbb/phpbb
Source
support@hackerone.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.