CVE-2005-3415: phpBB 2.0.17 and earlier allows remote attackers to bypass protection mechanisms that deregister global variab

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HIGH 7.5DOWNGRADE

CVE-2005-3415 is a high-severity flaw (CVSS 7.5) affecting phpbb. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

phpBB 2.0.17 and earlier allows remote attackers to bypass protection mechanisms that deregister global variables by setting both a GET/POST/COOKIE (GPC) variable and a GLOBALS[] variable with the same name, which causes phpBB to unset the GLOBALS[] variable but not the GPC variable.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
EPSS exploit chance	2.4% (top 16%)
CISA exploited list	No
Published	2005-11-01
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: phpbb group

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2005-11-01 21:02 UTCPublished CVE record published
2026-06-16 22:16 UTCUpdated Record last modified

phpbb group phpbb DOWNGRADE

Affected: 2.0.0 · 2.0.1 · 2.0.2 · 2.0.3 · 2.0.4 · 2.0.5 · 2.0.6 · 2.0.6c

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.0.0

1. Check installed version

apt-cache policy phpbb || rpm -q phpbb || phpbb --version

2. No fixed release: DOWNGRADE to a release before 2.0.0 (Debian / Ubuntu)

apt-cache madison phpbb sudo apt install phpbb=<VERSION_BEFORE_2.0.0> sudo apt-mark hold phpbb

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list phpbb sudo dnf downgrade phpbb-<VERSION_BEFORE_2.0.0> sudo dnf versionlock add phpbb

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2005-3415?

phpbb: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2005-3415 being exploited?

CVE-2005-3415 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2005-3415 affect?

CVE-2005-3415 affects phpbb. Severity is high (CVSS 7.5). phpBB 2.0.17 and earlier allows remote attackers to bypass protection mechanisms that deregister global variables by setting both a GET/POST/COOKIE (GPC) variable and a GLOBALS[] variable with the same name, which causes phpBB to unset the

How urgent is CVE-2005-3415?

Priority 47/100. High severity

Related CVEs

CVE-2026-29199 HIGH 8.1 UPGRADE phpBB before 3.3.16 is vulnerable to Host Header Injection that can lead to password rest link poisoning
CVE-2025-70811 MEDIUM 4.3 DOWNGRADE Cross Site Request Forgery vulnerability in Phpbb phbb3 v.3.3.15 allows a local attacker to execute arbitrary
CVE-2025-70810 HIGH 8.8 DOWNGRADE Cross Site Request Forgery vulnerability in Phpbb phbb3 v.3.3.15 allows a local attacker to execute arbitrary
CVE-2023-5917 LOW 2.4 UPGRADE A vulnerability, which was classified as problematic, has been found in phpBB up to 3.3.10
CVE-2020-8226 MEDIUM 5.8 UPGRADE A vulnerability exists in phpBB <v3.2.10 and <v3.3.1 which allowed remote image dimensions check to be used to

References

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