CVE-2015-7783: Cross-site scripting (XSS) vulnerability in Let's PHP! p++BBS before 4.10 allows remote attackers to inject ar

Routine

MEDIUM 6.1DOWNGRADE

CVE-2015-7783 is a medium-severity flaw (CVSS 6.1) affecting pbbs. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Cross-site scripting (XSS) vulnerability in Let's PHP! p++BBS before 4.10 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Why this priority

No elevated risk signals yet

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

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.0% (top 37%)
CISA exploited list	No
Weakness	CWE-79
Published	2015-12-27
Last modified	2026-06-17

Publisher (CNA): JPCERT/CC · Vendor: let\'s php\!

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2015-12-27 19:59 UTCPublished CVE record published
2026-06-17 00:33 UTCUpdated Record last modified

let\'s php\! pbbs DOWNGRADE

Affected: 4.05

Fixed in: no fixed release known

Safe to downgrade to: a release before 4.05

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 4.05 (Debian / Ubuntu)

apt-cache madison pbbs sudo apt install pbbs=<VERSION_BEFORE_4.05> sudo apt-mark hold pbbs

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

dnf --showduplicates list pbbs sudo dnf downgrade pbbs-<VERSION_BEFORE_4.05> sudo dnf versionlock add pbbs

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-2015-7783?

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

Is CVE-2015-7783 being exploited?

CVE-2015-7783 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-2015-7783 affect?

CVE-2015-7783 affects pbbs. Severity is medium (CVSS 6.1). Cross-site scripting (XSS) vulnerability in Let's PHP! p++BBS before 4.10 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

How urgent is CVE-2015-7783?

Priority 37/100. No elevated risk signals yet.

Software pages

PHP vulnerabilities

References

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