AB Download Manager before 1.11.2 Arbitrary File Write via /start-headless-download CSRF
AB Download Manager before 1.11.2 is exposed when run with default settings, which leave the browser-integration API on and its authentication off. Fixed in 1.11.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 1.11.2
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Browser-integration REST API is enabled by default API authentication is disabled by default A webpage open in the victim's browser while the app runs with default settings
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure12/25Specific setups only, reachable over the network without a login
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8.7/10CVSS 8.7
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
CVE-2026-121451 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (high) and affects ab-download-manager; fixed in 1.11.2.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 21/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 1.11.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
AB Download Manager, a download utility, is affected by this vulnerability. A malicious web page can exploit it to write files to arbitrary locations on a user's computer, potentially placing malicious code in startup folders so it runs when the user next logs in.
Read the original description
AB Download Manager before 1.11.2 contains a cross-site request forgery vulnerability in its unauthenticated browser-integration API that allows remote attackers to write attacker-chosen files to arbitrary paths. A malicious web page can send a text/plain request to /start-headless-download with crafted folder and name values, placing payloads in startup folders for code execution on next login.
What to do
Check whether your setup matches what the bug needs.
Browser-integration REST API is enabled by default API authentication is disabled by default A webpage open in the victim's browser while the app runs with default settingsUpgrade to a fixed version: 1.11.2.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- amir1376 ab-download-manager
fixed in 1.11.2
Evidence 6
- Patch
- Report
- Repository
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121451
Is CVE-2026-121451 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A webpage open in the browser while the app runs can direct it to download attacker-controlled content to an attacker-chosen absolute path. That path can be outside the downloads directory, such as an autostart location, and the download starts immediately without user interaction or confirmation.Source: github.com
Which versions are affected by CVE-2026-121451?
ab-download-manager: before 1.11.2.Source: cve.now feed data
Am I affected, and how do I check?
Versions before 1.11.2 are affected under default settings, where the browser-integration REST API is enabled (apiEnabled = true) and API authentication is disabled (apiAuthEnabled = false). The settings to check are apiEnabled and apiAuthEnabled, and the installed version number.Source: github.com
How do I fix CVE-2026-121451?
Upgrade AB Download Manager to 1.11.2 or later, which is the fixed version.Source: github.com