CVE-2016-9079

A use-after-free vulnerability in SVG Animation has been discovered. An exploit built on this vulnerability has been discovered in the wild targeting Firefox and Tor Browser users on Windows. This vulnerability affects Firefox < 50.0.2, Firefox ESR < 45.5.1, and Thunderbird < 45.5.1.

CVSS: 7.5Highscored by CISA
Exploited in the wild: Yes, in CISA KEV since 22 Jun 2023CISA deadline for US federal agencies: 13 Jul 2023public exploit code
EPSS: 87.4%chance of exploitation in the next 30 daystop 0.3% of scored CVEsFIRST score of 11 Nov 2026
Fix: Patch availablesee the advisories in the references
Published: 11 Jun 2018analysed here 12 Nov 2026

Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)

Summary

Triage

Attack surface: Server-side
Exploitable: At runtime
Attack vector: network
Weakness: CWE-416 Use After Free
Can a WAF block it?: No. See why

The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.

Affected products

Product	Affected versions	Vendor says fixed in
Mozilla Firefox	< 50.0.2Vendor says fixed in: not stated	Not stated by the vendor
Mozilla Firefox ESR	< 45.5.1Vendor says fixed in: not stated	Not stated by the vendor
Mozilla Thunderbird	< 45.5.1Vendor says fixed in: not stated	Not stated by the vendor

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

Products named in our analysis

debian:debian_linux
redhat:enterprise_linux
redhat:enterprise_linux_desktop
redhat:enterprise_linux_server
redhat:enterprise_linux_server_aus
redhat:enterprise_linux_server_eus
redhat:enterprise_linux_workstation
mozilla:thunderbird
mozilla:firefox
torproject:tor

Fix and mitigation

WAF and other mitigations

Can a WAF block it? No. This is a use-after-free memory bug. Generic WAF rules do not recognise the input that triggers it; only a rule written for this specific CVE can, and only if the triggering request has a recognisable shape.

Also consider: patch

Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

Remediation steps (AI-written)

Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.

Exploitation evidence

CISA KEV catalog: Listed since 22 Jun 2023.
CISA due date: 13 Jul 2023, the remediation deadline for US federal agencies
CISA required action: Apply updates per vendor instructions.
Public exploit code: Yes: 2 on Exploit-DB · 1 Metasploit module · 4 GitHub proofs of concept
CISA SSVC: exploitation active, automatable yes, technical impact partialAssessed by CISA 7 Feb 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

Exploit-DB

Firefox 50.0.1 - ASM.JS JIT-Spray Remote Code Executionremote, 14 Jul 2017
Mozilla Firefox < 50.0.2 - 'nsSMILTimeContainer::NotifyTimeChange()' Remote Code Execution (Metasploit)remote, 24 Jan 2017, verified by Exploit-DB

Metasploit

exploit/windows/browser/firefox_smil_uafexploit, rank normal

GitHub proofs of concept

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

Timeline

24 Jan 2017First public exploit or proof of concept
11 Jun 2018Published504 days (about 1 year) later
22 Jun 2023Added to CISA KEV (exploited in the wild)1,836 days (about 5 years) later
13 Jul 2023CISA remediation due date (US federal agencies)21 days later
7 Feb 2025CISA SSVC assessment: exploitation active576 days (about 2 years) later
21 Oct 2025CVE record last updated256 days (about 9 months) later
12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Metric	Value	What it means
Attack vector	NetworkReachable over the internet or any routable network.	Reachable over the internet or any routable network.
Attack complexity	LowRepeatable attack, no special conditions.	Repeatable attack, no special conditions.
Privileges required	NoneThe attacker needs no prior access.	The attacker needs no prior access.
User interaction	NoneNo victim action needed.	No victim action needed.
Scope	UnchangedImpact stays within the vulnerable component.	Impact stays within the vulnerable component.
Confidentiality	HighTotal data disclosure possible.	Total data disclosure possible.
Integrity	NoneNo unauthorised modification.	No unauthorised modification.
Availability	NoneThe service stays up.	The service stays up.

Common questions

Is CVE-2016-9079 being exploited?

Yes. CVE-2016-9079 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2016-9079?

CVE-2016-9079 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2016-9079?

Yes. A fix has been recorded for CVE-2016-9079. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2016-9079 affect?

CVE-2016-9079 affects debian:debian_linux, redhat:enterprise_linux, redhat:enterprise_linux_desktop, redhat:enterprise_linux_server, and 6 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

References

NVD CVE.org CVE Details Source

12 references in the CVE record, grouped by the tags the record gives them.

Advisories (5)

debian.org /security/2016/dsa-3730
rhn.redhat.com /errata/RHSA-2016-2843.html
security.gentoo.org /glsa/201701-35
rhn.redhat.com /errata/RHSA-2016-2850.html
security.gentoo.org /glsa/201701-15

Exploits (2)

exploit-db.com /exploits/42327/
exploit-db.com /exploits/41151/

Where the data on this page comes from

CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
NVD: CVSS and CPE data
CISA KEV catalog: exploitation, date added, due date
CISA Vulnrichment (ADP): SSVC decision points
FIRST EPSS: exploit probability and percentile
Exploit-DB: published exploits
Metasploit Framework: exploit and scanner modules
PoC-in-GitHub: GitHub repositories that claim a proof of concept

Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.

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