No exploitation reportedFix available

CVE-2020-9498

Q: Is CVE-2020-9498 actively exploited?

Active exploitation of CVE-2020-9498 has not been confirmed. Its EPSS score was 0.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-9498?

CVE-2020-9498 has a CVSS v3 base score of 6.7 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2020-07-02
Fixed in1.1.0
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Apache Guacamole 1.1.0 and older may mishandle pointers involved inprocessing data received via RDP static virtual channels. If a userconnects to a malicious or compromised RDP server, a series ofspecially-crafted PDUs could result in memory corruption, possiblyallowing arbitrary code to be executed with the privileges of therunning guacd process.

Timeline

dates in UTC

2020-07-0213:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-9498?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-9498?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV · NVD

guacamole

Branch	Affected	Fixed in	Source
1.1	< 1.1.0	1.1.0	OSV

Fedoraproject fedora

Branch	Affected	Fixed in	Source
32.x	= 32	no fix published	NVD
33.x	= 33	no fix published	NVD

Apache guacamole

Branch	Affected	Fixed in	Source
1.1	≤ 1.1.0	no fix published	NVD

2 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update guacamole to 1.1.0

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.16.7read 2026-10-23
NVDCVSS 2.06.2read 2026-10-23
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score0.7 %2026-10-23
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
Published: 2020-07-02
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-9498?

Is CVE-2020-9498 actively exploited?

Active exploitation of CVE-2020-9498 has not been confirmed. Its EPSS score was 0.7% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-9498?

CVE-2020-9498 has a CVSS v3 base score of 6.7 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.

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