CVE-2015-5123
CVE-2015-5123 is a security flaw in Adobe Flash Player, Adobe’s discontinued browser plug-in for animation and video. Attackers can run their own code on Adobe Flash Player. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 13 Apr 2022.[1]
Adobe Flash Player is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work.
Description
CISA calls it an use-after-free in Adobe Flash Player. In its words: “Use-after-free vulnerability in the BitmapData class in the ActionScript 3 (AS3) implementation in Adobe Flash Player allows remote attackers to execute code or cause a denial-of-service (DoS).”[1]
The CVE record adds: “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.”[2]
The underlying weakness is use after free (CWE-416), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it. CISA names the product as Adobe Flash Player.
Every device with Adobe Flash Player needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 13 Apr 2022, 2,465 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 4 May 2022 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 19%. That’s in the top 3% of the flaws it scores.[3]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
CISA’s required action: “The impacted product is end-of-life and should be disconnected if still in use.”[1]
- Update Adobe Flash Player now.Install the latest update from Adobe on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 19%.[3] |
See also
Other Adobe Flash Player flaws
- CVE-2014-0502: double free vulnerablity ·
- CVE-2014-0497: integer underflow vulnerablity ·
- CVE-2013-0648: code execution ·
- CVE-2013-0643: incorrect default permissions ·
- CVE-2012-5054: integer overflow ·
- CVE-2012-0767: cross-site scripting (XSS) ·
Other Adobe flaws
- CVE-2026-48356, Adobe Commerce and Magento: unrestricted upload of file with dangerous type ·
- CVE-2026-71362, Adobe Commerce and Magento: incorrect authorization ·
- CVE-2026-75650, Adobe Commerce and Magento: improper neutralization of special elements used in a template engine ·
- CVE-2026-48282, Adobe ColdFusion: path traversal ·
- CVE-2009-3459, Adobe Acrobat and Reader: heap-based buffer overflow ·
Other use after free flaws
- CVE-2026-109619, PHP: stale internal request-state ·
- CVE-2026-109618, PHP: memory corruption ·
- CVE-2026-68820, Microsoft Windows Ancillary Function Driver for WinSock: use-after-free ·
- CVE-2010-0249, Microsoft Internet Explorer: use-after-free ·
- CVE-2026-5281, Google Dawn: use-after-free ·
Added the same day
- CVE-2022-24521, Microsoft Windows: CLFS driver privilege escalation ·
- CVE-2018-7602, Drupal Core: remote code execution ·
- CVE-2018-20753, Kaseya Virtual System/Server Administrator (VSA): VSA remote code execution ·
- CVE-2015-5122, Adobe Flash Player: use-after-free ·
- CVE-2015-3113, Adobe Flash Player: heap-based buffer overflow ·
Every Adobe flaw on CISA’s list · Everything added in April 2022
References
- ^ Cybersecurity and Infrastructure Security Agency. “Adobe Flash Player Use-After-Free Vulnerability”. Known Exploited Vulnerabilities Catalog, added 13 Apr 2022.
- ^ National Institute of Standards and Technology. “CVE-2015-5123 Detail”. National Vulnerability Database, published 14 Jul 2015.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.188, percentile 97.3, 31 Oct 2026.
- CVE Program. “CVE-2015-5123”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.