CVE-2020-35906
futures_task::waker may cause a use-after-free if used on a type that isn't 'static
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
- Record
CVE-2020-35906- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.2 High
AV:L/AC:L/Au:N/C:C/I:C/A:C - Weakness
- CWE-416
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
- Record
CVE-2020-35906- Updated
- 2026-11-02
EUVDEUVD-2022-5135 No score
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
- Record
EUVD-2022-5135- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-r93v-9p5q-vhpf
futures_task::waker may cause a use-after-free if used on a type that isn't 'static
Affected versions of the crate did not properly implement a 'static lifetime bound on the waker function. This resulted in a use-after-free if Waker::wake() is called after original data had been dropped.
The flaw was corrected by adding 'static lifetime bound to the data waker takes.
- Record
GHSA-r93v-9p5q-vhpf- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSV
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
- Record
CVE-2020-35906- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-r93v-9p5q-vhpf
futures_task::waker may cause a use-after-free if used on a type that isn't 'static
Affected versions of the crate did not properly implement a 'static lifetime bound on the waker function. This resulted in a use-after-free if Waker::wake() is called after original data had been dropped.
The flaw was corrected by adding 'static lifetime bound to the data waker takes.
- Record
GHSA-r93v-9p5q-vhpf- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
OSVRUSTSEC-2020-0060
futures_task::waker may cause a use-after-free if used on a type that isn't 'static
Affected versions of the crate did not properly implement a 'static lifetime bound on the waker function.
This resulted in a use-after-free if Waker::wake() is called after original data had been dropped.
The flaw was corrected by adding 'static lifetime bound to the data waker takes.
- Record
RUSTSEC-2020-0060- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-35906
An issue was discovered in the futures-task crate before 0.3.6 for Rust. futures_task::waker may cause a use-after-free in a non-static type situation.
- Record
UBUNTU-CVE-2020-35906- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
futures-taskcrates.io |
0.2.1 up to 0.3.6 | 0.3.6 |
futures-taskcrates.io |
0.2.2-0 up to 0.3.6 | 0.3.6 |
rust-futures-taskUbuntu:22.04:LTS |
All versions, plus listed versions 0.3.8-10.3.17-1 |
None known |
rust-futures-taskUbuntu:24.04:LTS |
All versions, plus listed versions 0.3.28-10.3.29-10.3.30-1 |
None known |
rust-futures-taskUbuntu:25.10 |
All versions, plus listed versions 0.3.31-3 |
None known |
rust-futures-taskUbuntu:26.10 |
All versions, plus listed versions 0.3.31-30.3.32-10.3.33-1 |
None known |
rust-futures-taskUbuntu:26.04:LTS |
All versions, plus listed versions 0.3.31-3 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-35906 is a high vulnerability (CVSS 7.8) in Rust-lang Futures-task, published September 4, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.50%, the 43rd percentile. Fixed in futures-task 0.3.6.