CVE-2015-5123

Use-after-free vulnerability in the BitmapData class in the ActionScript 3 (AS3) implementation in Adobe Flash Player 13.x through 13.0.0.302 on Windows and OS X, 14.x through 18.0.0.203 on Windows and OS X, 11.x through 11.2.202.481 on Linux, and 12.x through 18.0.0.204 on Linux Chrome installations allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via crafted Flash content that overrides a valueOf function, as exploited in the wild in July 2015.

CVSS: 9.8Critical
Exploited in the wild: Yes, in CISA KEV since 13 Apr 2022CISA deadline for US federal agencies: 4 May 2022
EPSS: 18.8%chance of exploitation in the next 30 daystop 3% of scored CVEsFIRST score of 11 Nov 2026
Fix: Patch availablesee the advisories in the references
Published: 14 Jul 2015analysed here 12 Nov 2026

Do first. The impacted product is end-of-life and should be disconnected if still in use. (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

Products named in our analysis

redhat:enterprise_linux_desktop
redhat:enterprise_linux_server
redhat:enterprise_linux_server_eus
redhat:enterprise_linux_workstation
opensuse:evergreen
suse:linux_enterprise_desktop
suse:linux_enterprise_workstation_extension
adobe:flash_player
adobe:flash_player_desktop_runtime

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 13 Apr 2022.
CISA due date: 4 May 2022, the remediation deadline for US federal agencies
CISA required action: The impacted product is end-of-life and should be disconnected if still in use.
Public exploit code: None on record in Exploit-DB, Metasploit, Nuclei templates or PoC-in-GitHub.
CISA SSVC: exploitation active, automatable no, technical impact totalAssessed by CISA 17 Nov 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.

Timeline

14 Jul 2015Published
13 Apr 2022Added to CISA KEV (exploited in the wild)2,465 days (about 7 years) later
4 May 2022CISA remediation due date (US federal agencies)21 days later
17 Nov 2025CISA SSVC assessment: exploitation active1,294 days (about 4 years) later
17 Nov 2025CVE record last updatedsame day later
12 Nov 2026Analysed by vulneraibility.com360 days (about 12 months) later

CVSS vector

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

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	HighComplete modification possible.	Complete modification possible.
Availability	HighFull outage possible.	Full outage possible.

Common questions

Is CVE-2015-5123 being exploited?

Yes. CVE-2015-5123 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-2015-5123?

CVE-2015-5123 is rated Critical with a CVSS score of 9.8. 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-2015-5123?

Yes. A fix has been recorded for CVE-2015-5123. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2015-5123 affect?

CVE-2015-5123 affects redhat:enterprise_linux_desktop, redhat:enterprise_linux_server, redhat:enterprise_linux_server_eus, redhat:enterprise_linux_workstation, and 5 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

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

Advisories (9)

lists.opensuse.org /opensuse-security-announce/2015-07/msg00028.html
marc.info /?l=bugtraq&m=144050155601375&w=2
us-cert.gov /ncas/alerts/TA15-195A
kb.cert.org /vuls/id/918568
lists.opensuse.org /opensuse-security-announce/2015-07/msg00029.html
security.gentoo.org /glsa/201508-01

Show 3 more

h20564.www2.hp.com /portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c04796784
rhn.redhat.com /errata/RHSA-2015-1235.html
lists.opensuse.org /opensuse-security-announce/2015-07/msg00032.html

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

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

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