CVE-2016-9063: debian debian_linux Integer Overflow or Wraparound
Vulnerability summary
CVE-2016-9063 is a critical (CVSS 9.8) Integer Overflow or Wraparound vulnerability in debian debian_linux. EPSS estimates a 5.36% chance of exploitation in the next 30 days, higher than 92.6% of scored vulnerabilities.
Severe, CVSS 9.8 (NVD); no exploitation reported by the 5 checked sources; EPSS 5% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 14 · Related 12Timeline
- 11-06-2018PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
An integer overflow during the parsing of XML using the Expat library. This vulnerability affects Firefox < 50.
CVSS metrics
5 scores · 3 sources · 3 versions- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
5.36%
Chance of exploitation in the next 30 days
Percentile
93%
Versus all other CVEs
30-day change
Decrease -0.11 pp
From 5.47% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Debian3 products
- expat< 2.2.0-2
- libxmltokAll versions (No fix recorded)
- debian_linuxEOL8.0 | 9.0 | 10.0
Mozilla1 product
- firefox≥ unspecified, < 50 | < 50
Python1 product
- python≥ 2.7.0, < 2.7.15 | ≥ 3.3.0, < 3.3.7 | ≥ 3.4.0, < 3.4.7 | ≥ 3.5.0, < 3.5.4 | ≥ 3.6.0, < 3.6.2
Ubuntu1 product
- firefox< 50.0+build2-0ubuntu0.14.04.2 | < 50.0+build2-0ubuntu0.16.04.2
4 vendors · 6 products
