CVE-2008-6393: PSI Jabber client before 0.12.1 allows remote attackers to cause a denial of service (crash) and possibly exec

Q: How do I fix CVE-2008-6393?

psi: upgrade to newer than 0.12. Exact commands for each OS are on this page.

Q: Is CVE-2008-6393 being exploited?

CVE-2008-6393 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2008-6393 affect?

CVE-2008-6393 affects psi. Severity is high (CVSS 10.0). PSI Jabber client before 0.12.1 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a file transfer request with a negative value in a SOCKS5 option, which bypasses a signed integer check and

Q: How urgent is CVE-2008-6393?

Priority 64/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference

This week

HIGH 10.0UPGRADE

CVE-2008-6393 is a high-severity flaw (CVSS 10.0) affecting psi. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PSI Jabber client before 0.12.1 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a file transfer request with a negative value in a SOCKS5 option, which bypasses a signed integer check and triggers an integer overflow and a heap-based buffer overflow.

Why this priority

Critical severity
EPSS top 3%: very likely to be exploited
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	10.0 (High)
EPSS exploit chance	18.2% (top 3%)
CISA exploited list	No
Weakness	CWE-189
Published	2009-03-03
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: psi-im

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

Am I affected?

Timeline

2009-03-03 16:30 UTCPublished CVE record published
2026-06-16 23:02 UTCUpdated Record last modified

psi-im psi UPGRADE

Affected: <= 0.12 · 0.1.0 · 0.8.6 · 0.8.7 · 0.9 · 0.9.1 · 0.9.2 · 0.9.3

Fixed in: newer than 0.12

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to newer than 0.12 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade psi

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade psi

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Exploit-DB: Psi Jabber Client (Windows / Linux) - Remote Denial of Service

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-2008-6393?

psi: upgrade to newer than 0.12. Exact commands for each OS are on this page.

Is CVE-2008-6393 being exploited?

CVE-2008-6393 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-2008-6393 affect?

CVE-2008-6393 affects psi. Severity is high (CVSS 10.0). PSI Jabber client before 0.12.1 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a file transfer request with a negative value in a SOCKS5 option, which bypasses a signed integer check and

How urgent is CVE-2008-6393?

Priority 64/100. Critical severity; EPSS top 3%: very likely to be exploited; Public exploit reference

References

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