5.5

CVE-2025-66382: libexpat_project libexpat Inefficient Algorithmic Complexity

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2025-66382DEBIAN-CVE-2025-66382openSUSE-SU-2026:10087-1
Published 28-11-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-66382 is a medium (CVSS 5.5) Inefficient Algorithmic Complexity vulnerability in libexpat_project libexpat. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.5% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.20%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 28-11-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In libexpat through 2.7.3, a crafted file with an approximate size of 2 MiB can lead to dozens of seconds of processing time.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

0.00 pp

From 0.20% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu16 products
  • ayttmAll versions (No fix recorded)
  • cableswigAll versions (No fix recorded)
  • cadaverAll versions (No fix recorded)
  • coin3All versions (No fix recorded)
  • expatAll versions (No fix recorded)
Debian1 product
  • expatAll versions (No fix recorded)
Libexpat_project1 product
Opensuse1 product
  • tdom&distro=openSUSE Tumbleweed< 0.9.6-1.1

4 vendors · 19 products

References

9 links