Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.13, an unauthenticated attacker who can submit events to a Bugsink project can store arbitrary JavaScript in an event. The payload executes only if a user explicitly views the affected Stacktrace in the web UI. When Pygments returns more lines than it was given (a known upstream quirk that triggers with Ruby heredoc-style input), `_pygmentize_lines()` in `theme/templatetags/issues.py:75-77` falls back to returning the raw input lines. `mark_safe()` at line 111-113 is then applied unconditionally - including to those unsanitized raw lines. Since DSN endpoints are public by Sentry protocol, no account is needed to inject. The payload sits in the database until an admin looks at the event. Successful exploitation requires that the attacker to be able to submit events to the project (i.e. knows the DSN or can access a client that uses it), the Bugsink ingest endpoint is reachable to the attacker, and an administrator explicitly views the crafted event in the UI. Under those conditions, the attacker can execute JavaScript in the administrator’s browser and act with that user’s privileges within Bugsink. Version 2.0.13 fixes the vulnerability.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-vp6q-7m36-pq3w Bugsink is vulnerable to Stored XSS via Pygments fallback in stacktrace rendering
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 25 Feb 2026 12:00:00 +0000

Type Values Removed Values Added
First Time appeared Bugsink
Bugsink bugsink
Vendors & Products Bugsink
Bugsink bugsink

Wed, 25 Feb 2026 03:15:00 +0000

Type Values Removed Values Added
Description Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.13, an unauthenticated attacker who can submit events to a Bugsink project can store arbitrary JavaScript in an event. The payload executes only if a user explicitly views the affected Stacktrace in the web UI. When Pygments returns more lines than it was given (a known upstream quirk that triggers with Ruby heredoc-style input), `_pygmentize_lines()` in `theme/templatetags/issues.py:75-77` falls back to returning the raw input lines. `mark_safe()` at line 111-113 is then applied unconditionally - including to those unsanitized raw lines. Since DSN endpoints are public by Sentry protocol, no account is needed to inject. The payload sits in the database until an admin looks at the event. Successful exploitation requires that the attacker to be able to submit events to the project (i.e. knows the DSN or can access a client that uses it), the Bugsink ingest endpoint is reachable to the attacker, and an administrator explicitly views the crafted event in the UI. Under those conditions, the attacker can execute JavaScript in the administrator’s browser and act with that user’s privileges within Bugsink. Version 2.0.13 fixes the vulnerability.
Title Bugsink is vulnerable to Stored XSS via Pygments fallback in stacktrace rendering
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 9.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-25T20:01:45.861Z

Reserved: 2026-02-20T19:43:14.603Z

Link: CVE-2026-27614

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-25T03:16:05.803

Modified: 2026-02-25T14:15:29.980

Link: CVE-2026-27614

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-02-25T11:35:00Z

Weaknesses