CVE-2026-0883 | Information disclosure in the Networking component

Information disclosure in the Networking component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.

Published: 2026-01-13 Last update: 2026-04-13 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-0883 is rated Low Risk (23.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.03%). Mandatory action: 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-2026-0883

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 2026-01-14 0.03%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-0883

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N 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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 1.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-0883

OS Trackers for CVE-2026-0883

vendor priority summary link
alpine CVE-2026-0883: 3 source package rows (firefox, firefox-esr, thunderbird); 274 state rows across 2 repos (3.23-community, edge-community); fixed 0, open 274. https://security.alpinelinux.org/vuln/CVE-2026-0883
debian not yet assigned CVE-2026-0883 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. https://security-tracker.debian.org/tracker/CVE-2026-0883
redhat medium https://access.redhat.com/security/cve/CVE-2026-0883
suse high CVE-2026-0883 severity important: SUSE including 47 source package names (2.2.0-4.49:libopenssl3-3.1.4-slfo.1.1_5.1, 2.2.0-4.50:libopenssl3-3.1.4-slfo.1.1_5.1, …), 215 product×package rows across 87 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (87 product lines)): Fixed 211, First Fixed 4. https://www.suse.com/security/cve/CVE-2026-0883/
ubuntu medium CVE-2026-0883 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 58 status rows across 8 suites (bionic, focal, jammy, noble, plucky, questing, resolute, upstream): DNE 29, needs-triage 10, ignored 9, not-affected 9, released 1. https://ubuntu.com/security/CVE-2026-0883

Affected software / configurations for CVE-2026-0883

Vendor Product Version Raw CPE
mozilla firefox < 140.7.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:*
mozilla firefox < 147.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:*
mozilla thunderbird < 140.7.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:*
mozilla thunderbird < 147.0 cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:*

References for CVE-2026-0883

cvelogic Threat Intelligence