CVE-2008-6563: Buffer overflow in the XML parser in Trillian 3.1.9.0, and possibly earlier, allows remote attackers to cause

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HIGH 9.3DOWNGRADE

CVE-2008-6563 is a high-severity flaw (CVSS 9.3) affecting trillian. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Buffer overflow in the XML parser in Trillian 3.1.9.0, and possibly earlier, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted DTD file.

Why this priority

Critical severity
EPSS top 7%: very likely to be exploited
Public exploit reference

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

Risk facts

CVSS score	9.3 (High)
EPSS exploit chance	5.6% (top 7%)
CISA exploited list	No
Weakness	CWE-119
Published	2009-03-31
Last modified	2026-06-16

Publisher (CNA): MITRE · Vendor: ceruleanstudios

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

Am I affected?

Timeline

2009-03-31 17:30 UTCPublished CVE record published
2026-06-16 23:02 UTCUpdated Record last modified

ceruleanstudios trillian DOWNGRADE

Affected: 3.1.9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.1.9.0

1. Check installed version

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

2. No fixed release: DOWNGRADE to a release before 3.1.9.0 (Debian / Ubuntu)

apt-cache madison trillian sudo apt install trillian=<VERSION_BEFORE_3.1.9.0> sudo apt-mark hold trillian

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

dnf --showduplicates list trillian sudo dnf downgrade trillian-<VERSION_BEFORE_3.1.9.0> sudo dnf versionlock add trillian

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.

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: Trillian 3.1.9 - '.DTD' File XML Parser Buffer Overflow

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-2008-6563?

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

Is CVE-2008-6563 being exploited?

CVE-2008-6563 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-2008-6563 affect?

CVE-2008-6563 affects trillian. Severity is high (CVSS 9.3). Buffer overflow in the XML parser in Trillian 3.1.9.0, and possibly earlier, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted DTD file.

How urgent is CVE-2008-6563?

Priority 61/100. Critical severity; EPSS top 7%: very likely to be exploited; Public exploit reference

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References

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