Inefficient Algorithmic Complexity Affecting enshrined/svg-sanitize package, versions >=0.5.3, <1.1.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-PHP-ENSHRINEDSVGSANITIZE-22193078
- published4 Nov 2026
- disclosed27 Oct 2026
- creditAlpet Gexha
Introduced: 27 Oct 2026
NewCVE-2026-117540 (opens in a new tab)How to fix?
Upgrade enshrined/svg-sanitize to version 1.1.0 or higher.
Overview
enshrined/svg-sanitize is a SVG sanitizer for PHP
Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity via a quadratic-complexity code path in the sanitize() function when processing SVG input containing repeated PHP processing-instruction sequences. An attacker can submit a few-hundred-kilobyte upload that causes processing time to scale quadratically with input size, tying up a worker for tens of seconds and exhausting the worker pool with a handful of concurrent requests.
PoC
Generator emits `str_repeat('<?p', N) . '<?phpX?>' . str_repeat('hpY?>', N)` followed by a valid `<svg>`:
Measured end-to-end `sanitize()` time (default config):
| input size | time |
|-----------:|------|
| 32 KB | 0.16 s |
| 64 KB | 0.65 s |
| 128 KB | 2.48 s |
| 256 KB | 9.96 s |
| 384 KB | 22.2 s |
Doubling the input ~quadruples the time — textbook quadratic. A few-hundred-KB upload ties up a worker for tens of seconds; a few MB scales to minutes (input length is not bounded by the library, and because this is pre-parse string work, `allowHugeFiles` is irrelevant). A handful of concurrent requests exhausts the worker pool. No auth, no interaction, default config.
Note: The PoC states no specific environment, operating system, or non-default configuration.