libexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity amplification too late. Attackers can supply a moderately sized XML document with a large DTD and nested entity expansions to consume tens of seconds of CPU per parse.
Curated threat research and citations from CrowdStrike, Mandiant, Microsoft, and other sources — unlock with Premium.
Upgrade to Premium