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Mallory
HighPublic exploit

Prototype Pollution RCE in Adobe Acrobat Reader

IdentifiersCVE-2026-34622CWE-1321· Improperly Controlled Modification…

CVE-2026-34622 is a critical prototype pollution vulnerability in Adobe Acrobat Reader. Adobe describes the issue as an Improperly Controlled Modification of Object Prototype Attributes affecting Acrobat/Reader Continuous Track 26.001.21411 and earlier, Acrobat 2024 Classic Track 24.001.30362 and earlier on Windows, and 24.001.30360 and earlier on macOS. Successful exploitation can result in arbitrary code execution in the context of the current user. The provided content attributes the bug class to unsafe handling of JavaScript object prototype attributes within Acrobat Reader’s scripting environment when processing a malicious PDF. User interaction is required: the victim must open a crafted malicious file.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can lead to arbitrary code execution with the privileges of the logged-in user running Acrobat Reader. This can enable malware installation, data theft, and establishment of an initial foothold on the affected system. Because exploitation occurs in the context of the current user, impact depends on that user’s privileges and environment.

Mitigation

If you can’t patch tonight, do this now.

Until patching is completed, reduce exposure by preventing users from opening untrusted or unsolicited PDF files, especially those received via email or downloaded from the internet. In enterprise environments, restrict Acrobat/Reader use to trusted documents where possible and use attachment filtering, web download controls, and endpoint protections to reduce delivery of malicious PDFs. Prompt patch deployment is the primary mitigation.

Remediation

Patch, then assume compromise.

Upgrade Adobe Acrobat/Reader to a fixed release. The provided content states Adobe addressed CVE-2026-34622 in APSB26-44 and recommends updating Continuous Track installations to 26.001.21431 and Acrobat 2024 Classic Track installations to 24.001.30365. Apply vendor updates through the built-in updater, official Adobe installers, or enterprise software deployment tooling.
PUBLIC EXPLOITS

Exploits

1 valid exploit after Mallory filtered fakes, detection scripts, and README-only repos.

VALID 1 / 1 TOTALView more in app
CVE-2026-34621MaturityPoCVerified exploit

This repository is a small, self-contained research PoC for an Adobe Acrobat exploit chain centered on malicious PDF JavaScript execution and post-exploitation file theft. It contains 4 files: a Python PDF generator (CVE-2026-34621.py), a Python HTTP collection server (c2.py), the main Acrobat JavaScript payload (payload_steal.js), and documentation (ReadMe.md). The main exploit flow is: the operator embeds payload_steal.js into a PDF using CVE-2026-34621.py; the generated PDF sets /OpenAction to a JavaScript action so code runs when the document is opened; the JavaScript then abuses Acrobat-specific internal functions and trust mechanisms to obtain privileged execution; finally it reads a local Windows file and exfiltrates it over HTTP in chunks. CVE-2026-34621.py is not itself the vulnerability trigger beyond embedding arbitrary JavaScript into a PDF. It is a helper utility that reads an external JS file, escapes it for PDF syntax, and writes a minimal PDF object structure with /OpenAction pointing to a /JavaScript action. This makes it the delivery builder for the exploit document. payload_steal.js contains the actual exploit logic. It defines a privileged file-stealing routine using app.beginPriv(), util.readFileIntoStream(), and app.launchURL(). It hardcodes the victim file path /C/Windows/System32/drivers/etc/hosts and exfiltrates the resulting hex data to http://192.168.56.1:45191/exfil. The script also contains the exploit chain primitives described in the README: injection through ANFancyAlertImpl with a crafted button key, prototype pollution using Object.prototype.__defineGetter__('swConn', ...), trusted function registration via app.trustedFunction.bind, fake object methods for path processing, and invocation of ANShareFile/SilentDocCenterLogin to redirect privileged workflow execution. c2.py is a simple operational support component rather than the exploit itself. It listens on 0.0.0.0:45191, accepts GET requests to /exfil, reconstructs chunked hex data into binary, and saves recovered files under exfiltrated_files/. It prints progress and validates whether the recovered file begins with a PDF header. Overall, this is a real exploit PoC repository rather than a detector. It demonstrates a file-based attack vector against vulnerable Adobe Acrobat Reader environments, with a hardcoded but functional payload and a matching receiver, making it operational rather than a bare conceptual proof.

azefzafyoussefDisclosed May 12, 2026pythonjavascriptfileweblocal
EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
AdobeAcrobatapplication
AdobeAcrobat Dcapplication
AdobeAcrobat Readerapplication
AdobeAcrobat Reader Dcapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

16 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

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Exposure mapping

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Threat actor evidence

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Associated malware

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Detection signatures

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Vendor-by-vendor mapping

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Social activity12

Community discussion across Reddit, Mastodon, and other social sources.