CVE-2020-25574
Integer Overflow/Infinite Loop in the http crate
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- 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 http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
CVE-2020-25574- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-190, CWE-835
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
CVE-2020-25574- Updated
- 2026-11-02
EUVDEUVD-2021-1930 No score
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
EUVD-2021-1930- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x7vr-c387-8w57
Integer Overflow/Infinite Loop in the http crate
HeaderMap::reserve() used usize::next_power_of_two() to calculate the increased capacity. However, next_power_of_two() silently overflows to 0 if given a sufficiently large number in release mode.
If the map was not empty when the overflow happens, the library will invoke self.grow(0) and start infinite probing. This allows an attacker who controls the argument to reserve() to cause a potential denial of service (DoS).
The flaw was corrected in 0.1.20 release of http crate.
- Record
GHSA-x7vr-c387-8w57- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-190, CWE-835
- Updated
- 2026-11-02
OSV
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
CVE-2020-25574- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-25574
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
DEBIAN-CVE-2020-25574- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVGHSA-x7vr-c387-8w57
Integer Overflow/Infinite Loop in the http crate
HeaderMap::reserve() used usize::next_power_of_two() to calculate the increased capacity. However, next_power_of_two() silently overflows to 0 if given a sufficiently large number in release mode.
If the map was not empty when the overflow happens, the library will invoke self.grow(0) and start infinite probing. This allows an attacker who controls the argument to reserve() to cause a potential denial of service (DoS).
The flaw was corrected in 0.1.20 release of http crate.
- Record
GHSA-x7vr-c387-8w57- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-190, CWE-835
- Updated
- 2026-11-02
OSVGHSA-xvc9-xwgj-4cq9
Duplicate Advisory: Integer Overflow in HeaderMap::reserve() can cause Denial of Service
Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-x7vr-c387-8w57. This link is maintained to preserve external references.
Original Description
HeaderMap::reserve() used usize::next_power_of_two() to calculate the increased capacity. However, next_power_of_two() silently overflows to 0 if given a sufficiently large number in release mode.
If the map was not empty when the overflow happens, the library will invoke self.grow(0) and start infinite probing. This allows an attacker who controls the argument to reserve() to cause a potential denial of service (DoS).
The flaw was corrected in 0.1.20 release of http crate.
- Record
GHSA-xvc9-xwgj-4cq9- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-190
- Updated
- 2026-11-02
OSVRUSTSEC-2019-0033
Integer Overflow in HeaderMap::reserve() can cause Denial of Service
HeaderMap::reserve() used usize::next_power_of_two() to calculate the increased capacity.
However, next_power_of_two() silently overflows to 0 if given a sufficiently large number
in release mode.
If the map was not empty when the overflow happens,
the library will invoke self.grow(0) and start infinite probing.
This allows an attacker who controls the argument to reserve()
to cause a potential denial of service (DoS).
The flaw was corrected in 0.1.20 release of http crate.
- Record
RUSTSEC-2019-0033- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-25574
An issue was discovered in the http crate before 0.1.20 for Rust. An integer overflow in HeaderMap::reserve() could result in denial of service (e.g., an infinite loop).
- Record
UBUNTU-CVE-2020-25574- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
httpcrates.io |
before 0.1.20 | 0.1.20 |
rust-httpDebian:12 |
before 0.1.19-2 | 0.1.19-2 |
rust-httpDebian:13 |
before 0.1.19-2 | 0.1.19-2 |
rust-httpDebian:14 |
before 0.1.19-2 | 0.1.19-2 |
httpcrates.io From an advisory covering 2 CVEs |
before 0.1.20 | 0.1.20 |
httpcrates.io From an advisory covering 2 CVEs |
0.0.0-0 up to 0.1.20 | 0.1.20 |
rust-httpUbuntu:20.04:LTS |
All versions, plus listed versions 0.1.17-10.1.19-1 |
None known |
rust-httpUbuntu:24.04:LTS |
All versions, plus listed versions 0.2.7-10.2.9-1 |
None known |
rust-httpUbuntu:25.10 |
All versions, plus listed versions 1.2.0-1 |
None known |
rust-httpUbuntu:26.10 |
All versions, plus listed versions 1.3.1-11.4.0-11.5.0-1 |
None known |
rust-httpUbuntu:26.04:LTS |
All versions, plus listed versions 1.2.0-11.3.1-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| affected | ||
| 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-2020-25574 is a high vulnerability (CVSS 7.5) in Hyper Http, published November 16, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.53%, the 84th percentile. Fixed in http 0.1.20.