CVE-2026-12318 | Incorrect boundary conditions in the Libraries component in NSS

Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

Published: 2026-06-16 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-12318 is rated Low Risk (33.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.22%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-12318

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 2026-06-17 — 0.22% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-12318

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 3.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-12318

GitHub Security Advisory for CVE-2026-12318

GHSA-6q4q-pwxf-8h4v · Severity: high — Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in...

OS Trackers for CVE-2026-12318

vendor priority summary link
debian not yet assigned CVE-2026-12318 not yet assigned priority: Debian including 2 source packages (firefox, nss), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): undetermined 5, open 1. https://security-tracker.debian.org/tracker/CVE-2026-12318
suse critical — https://www.suse.com/security/cve/CVE-2026-12318/
ubuntu medium CVE-2026-12318 medium priority: Ubuntu including 10 source packages (firefox, mozjs102, …), 58 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 23, needs-triage 18, ignored 8, not-affected 7, needed 1, released 1. https://ubuntu.com/security/CVE-2026-12318

Affected software / configurations for CVE-2026-12318

Vendor Product Version Raw CPE
mozilla firefox < 152.0.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
mozilla thunderbird < 152.0.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

References for CVE-2026-12318

cvelogic Threat Intelligence