Answer in brief
CVE-2026-115506 records a High severity (CVSS 8.7) vulnerability in libexpat through 2.9.0 Denial of Service via Billion Laughs Detection Delay. The current sources do not mark it as known exploited. The current feed maps libexpat/libexpat (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps libexpat/libexpat (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| libexpat/libexpatgeneric | >=0 <=2.9.0 | Not reported |
Published upstream
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 22, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 22, 2026
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.
Quoted source text, attributed separately from HOL analysis.