Predictable shared file in AsyncHttpClient follows symlinks
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · High · Low
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
The AsyncHttpClient async-http-client package is affected from 2.0.0 before 2.16.1 and from 3.0.0 before 3.0.12. PropertiesBasedResumableProcessor stores resumable download state at a predictable shared path in the temporary directory with default permissions and follows symbolic links when it saves that state (CWE-61). A local user who can read the shared store can see download URLs, including user information or query tokens, and a local user who can write to that directory can plant a symbolic link so the client overwrites a file it can write.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
Description from the CNA
The AsyncHttpClient library allows Java applications to execute HTTP requests and asynchronously process HTTP responses. From 2.0.0 until 2.16.1 and 3.0.12, PropertiesBasedResumableProcessor stores resumable download state at the predictable shared path $java.io.tmpdir/ahc/ResumableAsyncHandler.properties with default permissions and link-following file operations. A local user who can read the shared store can see download URLs, including embedded user information or query tokens. A local user who can write within or pre-create the affected shared store directory can plant a symbolic link that the client follows when saving state, truncating and overwriting a target file writable by the client process. The filesystem path is used when ResumableAsyncHandler decorates another AsyncHandler, while the no-argument constructors use a no-op processor and are unaffected. This issue is fixed in versions 2.16.1 and 3.0.12.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| AsyncHttpClient | async-http-client | 2.0.0 to before 2.16.1; 3.0.0 to before 3.0.12 | 2.16.1, 3.0.12 | Patch available | CNA |
- async-http-client VendorAsyncHttpClient Affected 2.0.0 to before 2.16.1; 3.0.0 to before 3.0.12 Fixed in 2.16.1, 3.0.12 Patch available CNA
Remediation
Upgrade async-http-client to version 2.16.1 or 3.0.12. Red Hat Fuse 7 is affected, and Red Hat plans no fix for it.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
- Fix · CNA async-http-client (AsyncHttpClient) Fixed in 2.16.1, 3.0.12
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Fuse 7 | Affected | No fix planned: Out of support scope |
Timeline
- 2026-10-16 Threatist record created from CVE-2026-102740
- 2026-11-03 Affected versions changed · Red Hat
- 2026-11-03 CVSS score added · Red Hat
References
Other 6
- https://github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-cf59-3jcr-vfhw
- https://github.com/AsyncHttpClient/async-http-client/pull/2281
- https://github.com/AsyncHttpClient/async-http-client/commit/0422e11c954c4b026e986d1458f7a7a2eab7e591
- https://github.com/AsyncHttpClient/async-http-client/commit/d945ce3357b093e74526871cd309832a717ecfda
- https://github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-2.16.1
- https://github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-3.0.12
More AsyncHttpClient vulnerabilities
- TI-2024-36149 AsyncHttpClient (AHC) library's `CookieStore` replaces explicitly defined `Cookie`s CVSS 4.0CRITICAL 9.2
- TI-2026-69321 Cross-host replay in AsyncHttpClient leaks credentials to new host CVSS 4.0CRITICAL 9.4
- TI-2026-69315 AsyncHttpClient sends passwords in cleartext after Digest downgrade CVSS 4.0HIGH 8.7
- TI-2026-58825 AsyncHttpClient: Unbounded HTTP/1.1 response decompression enables a decompression-bomb denial of service CVSS 3.1HIGH 7.5
- TI-2026-69311 Unbounded WebSocket decompression in AsyncHttpClient enables DoS CVSS 3.1HIGH 7.5
- TI-2026-58823 AsyncHttpClient: SOCKS proxy credentials sent to the origin server over plaintext HTTP CVSS 3.1HIGH 7.5
Sources
- CVE-2026-102740 · CVE Program
- CVE-2026-102740 · NVD
- FIRST EPSS
- CVE-2026-102740 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences