Klaas van Schelven

11 exploits Active since Jul 2025
CVE-2026-44502 WRITEUP MEDIUM WRITEUP
Bugsink: SSRF bypass in `validate_webhook_url`
Bugsink is a self-hosted error tracking tool. Prior to 2.1.3, Bugsink’s webhook URL validation could be (partially) bypassed because of a mismatch in URL parsing. The original validation logic parsed webhook URLs with Python’s urllib.parse.urlparse, then sent the request with requests.post. For malformed inputs involving backslashes and @, those components can disagree about where the authority ends and which hostname is the real target. A URL may therefore appear to target an allowlisted public hostname during validation, while the HTTP client actually connects to a different host. This vulnerability is fixed in 2.1.3.
CVSS 4.3
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2026-27614 WRITEUP CRITICAL WRITEUP
Bugsink < 2.0.13 - Unauthenticated Stored Cross-Site Scripting via Pygments Line Handling
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.
CVSS 9.3
CVE-2025-54433 WRITEUP HIGH WRITEUP
Bugsink < 1.4.3, 1.5.0-1.5.4, 1.6.0-1.6.3, 1.7.0-1.7.3 - Path Traversal and Arbitrary File Write via Untrusted Event ID
Bugsink is a self-hosted error tracking service. In versions 1.4.2 and below, 1.5.0 through 1.5.4, 1.6.0 through 1.6.3, and 1.7.0 through 1.7.3, ingestion paths construct file locations directly from untrusted event_id input without validation. A specially crafted event_id can result in paths outside the intended directory, potentially allowing file overwrite or creation in arbitrary locations. Submitting such input requires access to a valid DSN, potentially exposing them. If Bugsink runs in a container, the effect is confined to the container’s filesystem. In non-containerized setups, the overwrite may affect other parts of the system accessible to that user. This is fixed in versions 1.4.3, 1.5.5, 1.6.4 and 1.7.4.
CVE-2025-64508 WRITEUP HIGH WRITEUP
Bugsink < 2.0.5 - Denial of Service via Brotli Decompression Bomb
Bugsink is a self-hosted error tracking tool. In versions prior to 2.0.5, brotli "bombs" (highly compressed brotli streams, such as many zeros) can be sent to the server. Since the server will attempt to decompress these streams before applying various maximums, this can lead to exhaustion of the available memory and thus a Denial of Service. This can be done if the `DSN` is known, which it is in many common setups (JavaScript, Mobile Apps). The issue is patched in Bugsink version `2.0.5`. The vulnerability is similar to, but distinct from, another brotli-related problem in Bugsink, GHSA-rrx3-2x4g-mq2h/CVE-2025-64509.
CVSS 7.5