CVE-2026-102740
AsyncHttpClient: Resumable download index store is created world-readable and follows a planted symlink
CVE-2026-102740 is a medium vulnerability (CVSS 5.8) in Asynchttpclient Async-http-client, published October 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.10%, the 0th percentile. No source names a fixed version.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
5.8
AsyncHttpClient: Resumable download index store is created world-readable and follows a planted symlink
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.
- Record
CVE-2026-102740- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-61, CWE-379, CWE-732
- Updated
- 2026-11-02
EUVDEUVD-2026-102223
5.8
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.
- Record
EUVD-2026-102223- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
NVD
5.8
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.
- Record
CVE-2026-102740- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-61, CWE-379, CWE-732
- Updated
- 2026-11-02
OSV
5.8
AsyncHttpClient: Resumable download index store is created world-readable and follows a planted symlink
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.
- Record
CVE-2026-102740- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-379, CWE-61, CWE-732
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-102740
5.8
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.
- Record
DEBIAN-CVE-2026-102740- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-102740
5.8
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.
- Record
UBUNTU-CVE-2026-102740- CVSS 3.1
- 5.8 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
async-http-clientDebian:12 |
All versions, plus listed versions 2.12.3-12.12.3-1+deb12u1 |
None known |
async-http-clientUbuntu:Pro:14.04:LTS |
All versions, plus listed versions 1.6.5-11.6.5-21.6.5-2ubuntu0.1~esm1 |
None known |
async-http-clientUbuntu:16.04:LTS |
All versions, plus listed versions 1.6.5-4 |
None known |
async-http-clientUbuntu:18.04:LTS |
All versions, plus listed versions 1.6.5-41.6.5-5 |
None known |
async-http-clientUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2.6.0-12.6.0-1ubuntu0.1~esm1 |
None known |
async-http-clientUbuntu:22.04:LTS |
All versions, plus listed versions 2.12.2-12.12.3-12.12.3-1ubuntu0.22.04.1 |
None known |
async-http-clientUbuntu:24.04:LTS |
All versions, plus listed versions 2.12.3-12.12.3-1ubuntu0.24.04.1 |
None known |
async-http-clientUbuntu:26.10 |
All versions, plus listed versions 2.12.3-1ubuntu1 |
None known |
async-http-clientUbuntu:26.04:LTS |
All versions, plus listed versions 2.12.3-12.12.3-1ubuntu12.12.3-1ubuntu1.1 |
None known |
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-02 | created | CVE List, EUVD, NVD, OSV |
References
github.com/AsyncHttpClient/async-http-client/security/advisories/GHSA-cf59-3jcr-vfhw
github.com/AsyncHttpClient/async-http-client/pull/2281
github.com/AsyncHttpClient/async-http-client/commit/0422e11c954c4b026e986d1458f7a7a2eab7e591
github.com/AsyncHttpClient/async-http-client/commit/d945ce3357b093e74526871cd309832a717ecfda
github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-2.16.1
github.com/AsyncHttpClient/async-http-client/releases/tag/async-http-client-project-3.0.12