PatchTheCVECVE-2008-5403: Heap-based buffer overflow in the XML parser in the AIM plugin in Trillian before 3.1.12.0 allows remote attac
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HIGH 10.0DOWNGRADEDOWNGRADEDOWNGRADE
CVE-2008-5403 is a high-severity flaw (CVSS 10.0) affecting trillian, trillian pro, trillian. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Heap-based buffer overflow in the XML parser in the AIM plugin in Trillian before 3.1.12.0 allows remote attackers to execute arbitrary code via a malformed XML tag.
Why this priority
- Critical severity
- EPSS top 5%: very likely to be exploited
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 10.0 (High) |
| EPSS exploit chance | 7.9% (top 5%) |
| CISA exploited list | No |
| Weakness | CWE-119 |
| Published | 2008-12-10 |
| Last modified | 2026-06-16 |
Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
cerulean studios trillian DOWNGRADE
Affected: 0.50 · 0.52 · 0.60 · 0.61 · 0.62 · 0.63 · 0.70 · 0.71
Fixed in: no fixed release known
Safe to downgrade to: a release before 0.50
1. Check installed version
apt-cache policy trillian || rpm -q trillian || trillian --version
2. No fixed release: DOWNGRADE to a release before 0.50 (Debian / Ubuntu)
apt-cache madison trillian
sudo apt install trillian=<VERSION_BEFORE_0.50>
sudo apt-mark hold trillian
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list trillian
sudo dnf downgrade trillian-<VERSION_BEFORE_0.50>
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.
cerulean studios trillian pro DOWNGRADE
Affected: all versions · 1.0 · 2.0 · 2.01 · 3.0 · 3.1.5.0 · 3.1_build_121
Fixed in: no fixed release known
Safe to downgrade to: a release before 1.0
1. Check installed version
apt-cache policy trillian-pro || rpm -q trillian-pro || trillian-pro --version
2. No fixed release: DOWNGRADE to a release before 1.0 (Debian / Ubuntu)
apt-cache madison trillian-pro
sudo apt install trillian-pro=<VERSION_BEFORE_1.0>
sudo apt-mark hold trillian-pro
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list trillian-pro
sudo dnf downgrade trillian-pro-<VERSION_BEFORE_1.0>
sudo dnf versionlock add trillian-pro
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.
ceruleanstudios trillian DOWNGRADE
Affected: all versions · 3.1.0.9 · 3.1.9.0
Fixed in: no fixed release known
Safe to downgrade to: a release before 3.1.0.9
1. Check installed version
apt-cache policy trillian || rpm -q trillian || trillian --version
2. No fixed release: DOWNGRADE to a release before 3.1.0.9 (Debian / Ubuntu)
apt-cache madison trillian
sudo apt install trillian=<VERSION_BEFORE_3.1.0.9>
sudo apt-mark hold trillian
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list trillian
sudo dnf downgrade trillian-<VERSION_BEFORE_3.1.0.9>
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.
ceruleanstudios trillian pro DOWNGRADE
Affected: all versions · 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-pro || rpm -q trillian-pro || trillian-pro --version
2. No fixed release: DOWNGRADE to a release before 3.1.9.0 (Debian / Ubuntu)
apt-cache madison trillian-pro
sudo apt install trillian-pro=<VERSION_BEFORE_3.1.9.0>
sudo apt-mark hold trillian-pro
2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)
dnf --showduplicates list trillian-pro
sudo dnf downgrade trillian-pro-<VERSION_BEFORE_3.1.9.0>
sudo dnf versionlock add trillian-pro
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.
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-2008-5403?
trillian: downgrade or apply the listed mitigation; trillian pro: downgrade or apply the listed mitigation; trillian: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2008-5403 being exploited?
CVE-2008-5403 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-2008-5403 affect?
CVE-2008-5403 affects trillian, trillian pro, trillian. Severity is high (CVSS 10.0). Heap-based buffer overflow in the XML parser in the AIM plugin in Trillian before 3.1.12.0 allows remote attackers to execute arbitrary code via a malformed XML tag.
How urgent is CVE-2008-5403?
Priority 59/100. Critical severity; EPSS top 5%: very likely to be exploited
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