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Threats / Mozilla / CVE-2016-9079
CVE-2016-9079 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Mozilla Firefox, Firefox ESR, and Thunderbird vulnerability

Use-after-free vulnerability in SVG Animation affecting Mozilla Firefox, Firefox ESR, and Thunderbird. Exploited in the wild with high exploitation probability.

Verdict

Today item — known-exploited.

A use-after-free flaw in SVG Animation processing allows attackers to execute arbitrary code through malicious SVG content. Active exploitation in the wild indicates immediate risk to users of affected Mozilla products.

CISA KEV Yes · 2023-06-223EPSS 0.87921 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2023-06-22).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.87921 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Mozilla, Firefox, Firefox ESR, and Thunderbird. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-416 Use After Free — weakness family: Memory safety.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
WeaknessCWE-416 · Use After FreeMemory safety
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution not established

No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.

03

Why it matters

— the attack path, told twice: adversary, then board
1

Front door — unauthenticated access narrative 1

Attacker
Craft malicious SVG content that triggers improper memory handling in the animation parser
Business
User systems compromised through browser exploitation, enabling data theft, malware installation, or lateral network movement
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
Deliver the malicious SVG via web pages, email attachments, or compromised websites
Business
Widespread user compromise across consumer and enterprise endpoints running vulnerable Firefox or Thunderbird versions
3

Lateral reach — past segmentation narrative 3

Attacker
Achieve code execution with browser process privileges to establish persistence or exfiltrate credentials
Business
Organizational data breach, credential compromise, and potential supply chain impact if targeted at enterprise users
04

What to do

— defensible action
  • Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05

Coverage & confidence

— what we know, and what we don’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • Public PoC available (VulnCheck)
  • 3 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mozilla (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by mozillaCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.