inftrees.c in zlib 1.2.8 might allow context-dependent attackers to have unspecified impact by leveraging improper pointer arithmetic.
Conclusion & alert: CVE-2016-9840 is rated High Risk (65.1/100): CVSS High severity, with high exploitation likelihood (EPSS 9.83%, 93th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-06 | 12.52% | 9.83% | -2.69% |
| 2 | 2026-05-28 | 9.72% | 12.52% | +2.80% |
| 3 | 2026-05-23 | — | 9.72% | — |
Full EPSS history (44 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | [email protected] |
| 6.8 | 2.0 | MEDIUM |
|
8.6 | 6.4 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2016-9840 not yet assigned priority: Debian including 2 source packages (rsync, zlib), 10 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10. | https://security-tracker.debian.org/tracker/CVE-2016-9840 |
gentoo
|
normal | CVE-2016-9840: 2 GLSA(s) (201701-56, 202007-54), 2 atom(s) (net-misc/rsync, sys-libs/zlib); latest impact normal. | https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2016-9840 |
redhat
|
low | — | https://access.redhat.com/security/cve/CVE-2016-9840 |
suse
|
critical | CVE-2016-9840 severity critical: SUSE including 597 source package names (0.9.1:libz1-1.2.8-11.1, 1.0.0:libz1-1.2.8-11.1, …), 2838 product×package rows across 361 product lines (Container bci/kiwi, Container caasp/v4/default-http-backend, … (361 product lines)): Fixed 2499, Known Affected 226, Known Not Affected 113. | https://www.suse.com/security/cve/CVE-2016-9840/ |
ubuntu
|
low | CVE-2016-9840 low priority: Ubuntu including 4 source packages (klibc, rsync, zlib, zsync), 61 status rows across 23 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, precise, questing, trusty, upstream, xenial, yakkety, zesty): released 28, not-affected 18, needs-triage 9, ignored 5, needed 1. | https://ubuntu.com/security/CVE-2016-9840 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| boost | boost | < 1.78.0 | cpe:2.3:a:boost:boost:*:*:*:*:*:*:*:* |
| zlib | zlib | >= 1.2.0.6, < 1.2.9 | cpe:2.3:a:zlib:zlib:*:*:*:*:*:*:*:* |
| opensuse | leap | 42.1 | cpe:2.3:o:opensuse:leap:42.1:*:*:*:*:*:*:* |
| opensuse | leap | 42.2 | cpe:2.3:o:opensuse:leap:42.2:*:*:*:*:*:*:* |
| opensuse | opensuse | 13.2 | cpe:2.3:o:opensuse:opensuse:13.2:*:*:*:*:*:*:* |
| debian | debian_linux | 8.0 | cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* |
| canonical | ubuntu_linux | 16.04 | cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:* |
| canonical | ubuntu_linux | 18.04 | cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:esm:*:*:* |
| oracle | database_server | 18c | cpe:2.3:a:oracle:database_server:18c:*:*:*:*:*:*:* |
| oracle | jdk | 1.6.0 | cpe:2.3:a:oracle:jdk:1.6.0:update161:*:*:*:*:*:* |
| oracle | jdk | 1.7.0 | cpe:2.3:a:oracle:jdk:1.7.0:update151:*:*:*:*:*:* |
| oracle | jdk | 1.8.0 | cpe:2.3:a:oracle:jdk:1.8.0:update144:*:*:*:*:*:* |
| oracle | jre | 1.6.0 | cpe:2.3:a:oracle:jre:1.6.0:update161:*:*:*:*:*:* |
| oracle | jre | 1.7.0 | cpe:2.3:a:oracle:jre:1.7.0:update151:*:*:*:*:*:* |
| oracle | jre | 1.8.0 | cpe:2.3:a:oracle:jre:1.8.0:update144:*:*:*:*:*:* |
| oracle | mysql | >= 5.5.0, <= 5.5.61 | cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:* |
| oracle | mysql | >= 5.6.0, <= 5.6.41 | cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:* |
| oracle | mysql | >= 5.7.0, <= 5.7.23 | cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:* |
| oracle | mysql | >= 8.0.0, <= 8.0.12 | cpe:2.3:a:oracle:mysql:*:*:*:*:*:*:*:* |
| redhat | satellite | 5.8 | cpe:2.3:a:redhat:satellite:5.8:*:*:*:*:*:*:* |
| redhat | enterprise_linux_desktop | 6.0 | cpe:2.3:o:redhat:enterprise_linux_desktop:6.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_desktop | 7.0 | cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_eus | 7.4 | cpe:2.3:o:redhat:enterprise_linux_eus:7.4:*:*:*:*:*:*:* |
| redhat | enterprise_linux_eus | 7.5 | cpe:2.3:o:redhat:enterprise_linux_eus:7.5:*:*:*:*:*:*:* |
| redhat | enterprise_linux_server | 6.0 | cpe:2.3:o:redhat:enterprise_linux_server:6.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_server | 7.0 | cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_workstation | 6.0 | cpe:2.3:o:redhat:enterprise_linux_workstation:6.0:*:*:*:*:*:*:* |
| redhat | enterprise_linux_workstation | 7.0 | cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* |
| apple | iphone_os | < 11 | cpe:2.3:o:apple:iphone_os:*:*:*:*:*:*:*:* |
| apple | mac_os_x | >= 10.0.0, < 10.13.0 | cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:* |
| apple | tvos | < 11.0 | cpe:2.3:o:apple:tvos:*:*:*:*:*:*:*:* |
| apple | watchos | < 4 | cpe:2.3:o:apple:watchos:*:*:*:*:*:*:*:* |
| nodejs | node.js | >= 4.0.0, <= 4.1.2 | cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:* |
| nodejs | node.js | >= 4.2.0, < 4.8.2 | cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:* |
| nodejs | node.js | >= 6.0.0, <= 6.8.1 | cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:* |
| nodejs | node.js | >= 6.9.0, < 6.10.2 | cpe:2.3:a:nodejs:node.js:*:*:*:*:lts:*:*:* |
| nodejs | node.js | >= 7.0.0, < 7.6.0 | cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:* |