CVE-2020-35905
MutexGuard::map can cause a data race in safe code
An issue was discovered in the futures-util crate before 0.3.7 for Rust. MutexGuard::map can cause a data race for certain closure situations (in safe code).
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
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the futures-util crate before 0.3.7 for Rust. MutexGuard::map can cause a data race for certain closure situations (in safe code).
- Record
CVE-2020-35905- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 1.9 Low
AV:L/AC:M/Au:N/C:N/I:N/A:P - Weakness
- CWE-362
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the futures-util crate before 0.3.7 for Rust. MutexGuard::map can cause a data race for certain closure situations (in safe code).
- Record
CVE-2020-35905- Updated
- 2026-11-02
EUVDEUVD-2022-5172 No score
An issue was discovered in the futures-util crate before 0.3.7 for Rust. MutexGuard::map can cause a data race for certain closure situations (in safe code).
- Record
EUVD-2022-5172- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-rh4w-94hh-9943
MutexGuard::map can cause a data race in safe code
Affected versions of the crate had a Send/Sync implementation for MappedMutexGuard that only considered variance on T, while MappedMutexGuard dereferenced to U.
This could of led to data races in safe Rust code when a closure used in MutexGuard::map() returns U that is unrelated to T.
The issue was fixed by fixing Send and Sync implementations, and by adding a PhantomData<&'a mut U> marker to the MappedMutexGuard type to tell the compiler that the guard is over U too.
- Record
GHSA-rh4w-94hh-9943- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-362
- Updated
- 2026-11-02
OSV
An issue was discovered in the futures-util crate before 0.3.7 for Rust. MutexGuard::map can cause a data race for certain closure situations (in safe code).
- Record
CVE-2020-35905- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-rh4w-94hh-9943
MutexGuard::map can cause a data race in safe code
Affected versions of the crate had a Send/Sync implementation for MappedMutexGuard that only considered variance on T, while MappedMutexGuard dereferenced to U.
This could of led to data races in safe Rust code when a closure used in MutexGuard::map() returns U that is unrelated to T.
The issue was fixed by fixing Send and Sync implementations, and by adding a PhantomData<&'a mut U> marker to the MappedMutexGuard type to tell the compiler that the guard is over U too.
- Record
GHSA-rh4w-94hh-9943- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-362
- Updated
- 2026-11-02
OSVRUSTSEC-2020-0059
MutexGuard::map can cause a data race in safe code
Affected versions of the crate had a Send/Sync implementation for MappedMutexGuard that only considered variance on T, while MappedMutexGuard dereferenced to U.
This could of led to data races in safe Rust code when a closure used in MutexGuard::map() returns U that is unrelated to T.
The issue was fixed by fixing Send and Sync implementations, and by adding a PhantomData<&'a mut U> marker to the MappedMutexGuard type to tell the compiler that the guard is over
U too.
- Record
RUSTSEC-2020-0059- CVSS 3.1
- 4.7 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVopenSUSE-SU-2024:11751-1 No score
afterburn-5.0.0-6.1 on GA media
These are all security issues fixed in the afterburn-5.0.0-6.1 package on the GA media of openSUSE Tumbleweed.
- Record
openSUSE-SU-2024:11751-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
futures-utilcrates.io |
0.3.2 up to 0.3.7 | 0.3.7 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | ||
| 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-2020-35905 is a medium vulnerability (CVSS 4.7) in Rust-lang Future-utils, published October 22, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. Fixed in futures-util 0.3.7.