Security Vulnerabilities
commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-09-07
league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-09-07
league/commonmark (thephpleague/commonmark) versions >= 2.7.0 and < 2.9.1 contain a cross-site scripting vulnerability in the AttributesExtension. Prefixing an attribute name with a single U+000C form feed byte (e.g. {\x0Conclick="alert(1)"}) bypasses the AttributesHelper::filterAttributes() 'on*' event-handler filter because PHP's trim() does not strip U+000C, causing the attribute to be written verbatim into the output where browsers parse it as a genuine event handler. The same prefix also defeats the allow_unsafe_links check, allowing javascript: URIs through href/src attributes even when allow_unsafe_links is false. Exploitation requires processing untrusted Markdown with the AttributesExtension enabled; the injected script executes when the rendered HTML is viewed. Fixed in 2.9.1.
CVSS Score
6.9
EPSS Score
0.002
Published
2026-09-07
The league/commonmark (thephpleague/commonmark) library in versions >= 1.5.0 and < 2.9.1 contains quadratic parsing complexity in its SmartPunctExtension and AttributesExtension. When either extension is explicitly registered on the Environment (they are not enabled by default and are excluded from the standard CommonMark and GitHub-Flavored Markdown converters), an unauthenticated attacker can submit small, specially crafted Markdown documents — such as text alternating with unpaired quotes, contiguous runs of block-level attribute blocks, or repeated class attributes — to trigger disproportionate CPU consumption and cause a denial of service. Fixed in 2.9.1.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-09-07
ImageMagick before 7.1.2-30 contains a time-of-check-time-of-use vulnerability in path policy enforcement on Windows that allows attackers to bypass read or write restrictions by exploiting symlink race conditions. Attackers can swap symlinks between policy validation and file access to read or write policy-denied files.
CVSS Score
1.0
EPSS Score
0.001
Published
2026-09-07
ImageMagick before 7.1.2-30 and 6.9.x before 6.9.13-55 contains a heap-use-after-free vulnerability in the GetList method of PerlMagick. A crafted call to the GetList method can trigger the use-after-free, resulting in a crash (denial of service).
CVSS Score
4.8
EPSS Score
0.001
Published
2026-09-07
ImageMagick before 7.1.2-30 and 6.9.x before 6.9.13-55 contains a heap-use-after-free vulnerability in the Layer method of PerlMagick. An attacker who supplies a crafted list of images can trigger memory access after deallocation, resulting in a crash (denial of service).
CVSS Score
4.8
EPSS Score
0.001
Published
2026-09-07
LibreNMS before 26.8.0 contains an authentication bypass vulnerability in the REST API that allows unauthenticated attackers to access protected endpoints by sending numeric values instead of string tokens. Attackers can exploit MySQL type coercion by sending small integers like 0 through 9 to match token hashes, gaining access to API functionality including device credentials and administrative features that enable remote code execution through alert templates.
CVSS Score
9.2
EPSS Score
0.021
Published
2026-09-07
LibreNMS before 26.8.0 contains an argument injection vulnerability in the graph_title parameter that allows authenticated attackers to inject arbitrary rrdtool arguments by breaking out of double-quote escaping. Attackers can inject DEF and LINE arguments to read RRD files from unauthorized devices, or use newline injection to execute arbitrary rrdtool commands, bypassing per-device authorization checks.
CVSS Score
8.7
EPSS Score
0.003
Published
2026-09-07
ImageMagick before 7.1.2-30 and 6.9.13-55 contains a time-of-check-time-of-use (TOCTOU) vulnerability in the video decoder that allows attackers to bypass path policy write restrictions via symlink swaps. An attacker can replace a symlink between policy validation (check-time) and the file write operation (use-time) to write to policy-denied locations.
CVSS Score
2.0
EPSS Score
0.001
Published
2026-09-07