Description
An issue was discovered in compare_digest in Lib/hmac.py in Python through 3.9.1. Constant-time-defeating optimisations were possible in the accumulator variable in hmac.compare_digest.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | pypy3 | 7.3.5+dfsg-2 | — |
| Debian 13 | pypy3 | 7.3.5+dfsg-2 | — |
| Debian 12 | pypy3 | 7.3.5+dfsg-2 | — |
| Debian 10 | python2.7 | 2.7.16-2+deb10u3 | DLA-3575-1 |
| Debian 10 | python3.7 | 3.7.3-2+deb10u6 | DLA-3614-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | python2.7 | 2.7.18-13ubuntu1.5 | USN-7180-1 |
| Ubuntu 22.04 LTS | python3.10 | 3.10.12-1~22.04.4 | USN-6891-1 |
| Ubuntu 20.04 LTS | python2.7 | 2.7.18-1~20.04.7 | USN-7180-1 |
| Ubuntu 20.04 LTS | python3.8 | 3.8.10-0ubuntu1~20.04 | USN-6891-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 22.04 LTS | python3.11 | 3.11.0~rc1-1~22.04.1~esm1 | USN-6891-1 |
| Ubuntu Pro 20.04 LTS | python3.9 | 3.9.5-3ubuntu0~20.04.1+esm2 | USN-6891-1 |
| Ubuntu Pro 18.04 LTS | python2.7 | 2.7.17-1~18.04ubuntu1.13+esm2 | USN-6400-1 |
| Ubuntu Pro 18.04 LTS | python3.6 | 3.6.9-1~18.04ubuntu1.13+esm2 | USN-6891-1 |
| Ubuntu Pro 18.04 LTS | python3.7 | 3.7.5-2ubuntu1~18.04.2+esm3 | USN-6891-1 |
| Ubuntu Pro 18.04 LTS | python3.8 | 3.8.0-3ubuntu1~18.04.2+esm2 | USN-6891-1 |
| Ubuntu Pro 16.04 LTS | python2.7 | 2.7.12-1ubuntu0~16.04.18+esm7 | USN-6400-1 |
| Ubuntu Pro 16.04 LTS | python3.5 | 3.5.2-2ubuntu0~16.04.13+esm11 | USN-6891-1, USN-6400-1 |
| Ubuntu Pro 14.04 LTS | python2.7 +1 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | python3.5 | 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1 | USN-6891-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | python +1 | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
| SLES 15 SP5 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLES 15 SP4 | python-base | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
| SLES 15 SP4 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLES 15 SP3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLES 12 SP5 | python +2 | 2.7.18-33.26.1 | SUSE-SU-2023:4001-1 |
| SLES 12 SP5 | python36 +1 | 3.6.15-55.1 | SUSE-SU-2024:1847-1 |
Show 15 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP4 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLES for SAP 15 SP3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLES for SAP 12 SP5 | python +2 | 2.7.18-33.26.1 | SUSE-SU-2023:4001-1 |
| SLES for SAP 12 SP5 | python36 +1 | 3.6.15-55.1 | SUSE-SU-2024:1847-1 |
| SLE Micro 5.5 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLE Micro 5.4 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLE Micro 5.3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLE Micro 5.2 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLE Micro 5.1 | python3 +1 | 3.6.15-150000.3.138.1 | SUSE-SU-2024:0464-1 |
| SLE HPC 15 SP4 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SLE HPC 15 SP3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SUSE Manager Server 4.3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SUSE Manager Server 4.2 | python +1 | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
| SUSE Manager Proxy 4.3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| SUSE Manager Proxy 4.2 | python +1 | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
| SUSE Enterprise Storage 7.1 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | python | 2.7.18-39.1 | openSUSE-SU-2024:13253-1 |
| openSUSE Leap 15.5 | python +2 | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
| openSUSE Leap 15.5 | python3 +2 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| openSUSE Leap 15.4 | python +2 | 2.7.18-150000.57.1 | SUSE-SU-2023:4220-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap Micro 5.4 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
| openSUSE Leap Micro 5.3 | python3 +1 | 3.6.15-150300.10.57.1 | SUSE-SU-2024:0901-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | python +6 | 2.7.18-1.amzn2.0.8 | ALAS2-2024-2400 |
| Amazon Linux 2 | python3 +6 | 3.7.10-1.amzn2.0.1 | ALAS2-2023-2317 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | python-py | No fix yet | — |
Advisories 15
- USN-6891-1 python3.5, python3.6, python3.7, python3.8, python3.9, python3.10, python3.11, python3.12 vulnerabilities Ubuntu Security Notices (USN) · Oct 8, 2026
- USN-6400-1 python2.7, python3.5 vulnerability Ubuntu Security Notices (USN) · Jun 25, 2026
- USN-7180-1 python2.7 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DLA-3575-1 python2.7 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3614-1 python3.7 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2023:4220-1 Security update for python SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:1847-1 Security update for python36 SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13253-1 python-2.7.18-39.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4001-1 Security update for python SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:0464-1 Security update for python3 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:0901-1 Security update for python3 SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-2119 Python: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 29, 2025
- WID-SEC-2025-0225 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 1, 2025
- ALAS2-2023-2317 Important: python3 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 8, 2025
- ALAS2-2024-2400 Moderate: python security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 9, 2024