CVE-2026-32243

MEDIUMCVSS 5.3/10EPSS 0.17%

Last modified

CVE-2026-32243 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an attacker with the ability to create shared AI conversations could inject arbitrary HTML and JavaScript via crafted conversation titles. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an attacker with the ability to create shared AI conversations could inject arbitrary HTML and JavaScript via crafted conversation titles. This payload would execute in the browser of any user viewing the onebox preview, potentially allowing session hijacking or unauthorized actions on behalf of the victim. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

Metrics

CVSS 3.1
5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS 4.0
5.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.17%

6.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
DiscourseDiscourse>= 2026.1.0, < 2026.1.3
DiscourseDiscourse>= 2026.2.0, < 2026.2.2
DiscourseDiscourse2026.3.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-32243?
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an attacker with the ability to create shared AI conversations could inject arbitrary HTML and JavaScript via crafted conversation titles. This payload would execute in the browser of any user viewing the onebox preview, potentially allowing session hijacking or unauthorized actions on behalf of the victim. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.
How severe is CVE-2026-32243?
CVE-2026-32243 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-32243?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-32243?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST