CVE-2023-40217: python
Vulnerability summary
CVE-2023-40217 is a medium (CVSS 5.3) vulnerability in python. EPSS estimates a 0.80% chance of exploitation in the next 30 days, higher than 56.5% of scored vulnerabilities.
Not severe (CVSS 5.3, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 16 · Related 13Timeline
- 25-08-2023PublishedVulnerability first disclosed.
- 03-11-2025Last modifiedVulnerability information updated.
Description
An issue was discovered in Python before 3.8.18, 3.9.x before 3.9.18, 3.10.x before 3.10.13, and 3.11.x before 3.11.5. It primarily affects servers (such as HTTP servers) that use TLS client authentication. If a TLS server-side socket is created, receives data into the socket buffer, and then is closed quickly, there is a brief window where the SSLSocket instance will detect the socket as "not connected" and won't initiate a handshake, but buffered data will still be readable from the socket buffer. This data will not be authenticated if the server-side TLS peer is expecting client certificate authentication, and is indistinguishable from valid TLS stream data. Data is limited in size to the amount that will fit in the buffer. (The TLS connection cannot directly be used for data exfiltration because the vulnerable code path requires that the connection be closed on initialization of the SSLSocket.)
CVSS metrics
5 scores · 5 sources · 1 version- OSV · AlpineEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · Red hatEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NDiffers
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.80%
Chance of exploitation in the next 30 days
Percentile
57%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.80% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Redhat156 products
- babel< 0:2.5.1-9.module+el8.1.0+3111+de3f2d8e | < 0:2.5.1-10.module+el8.5.0+11014+88fc0d0b
- Cython< 0:0.28.1-7.module+el8.1.0+3111+de3f2d8e | < 0:0.29.21-5.module+el8.4.0+9822+20bf1249
- Cython-debugsource< 0:0.28.1-7.module+el8.1.0+3111+de3f2d8e | < 0:0.29.21-5.module+el8.4.0+9822+20bf1249
- mod_wsgi< 0:4.7.1-5.module+el8.7.0+16654+645aad7f | < 0:4.7.1-4.module+el8.4.0+9822+20bf1249
- numpy< 1:1.14.2-13.module+el8.1.0+3323+7ac3e00f | < 1:1.14.2-16.module+el8.4.0+9406+221a4565 | < 0:1.19.4-3.module+el8.5.0+12204+54860423 | < 0:1.19.4-2.module+el8.4.0+15042+dc5a279b.1
Opensuse30 products
- python-base&distro=openSUSE Leap 15.4< 2.7.18-150000.54.1
- python-base&distro=openSUSE Leap 15.5< 2.7.18-150000.54.1
- python-doc&distro=openSUSE Leap 15.4< 2.7.18-150000.54.1
- python-doc&distro=openSUSE Leap 15.5< 2.7.18-150000.54.1
- python3-core&distro=openSUSE Leap 15.4< 3.6.15-150300.10.51.1
Ubuntu9 products
- python2.7< 2.7.6-8ubuntu0.6+esm18 | < 2.7.12-1ubuntu0~16.04.18+esm9 | < 2.7.17-1~18.04ubuntu1.13+esm4 | < 2.7.18-1~20.04.7 | < 2.7.18-13ubuntu1.5
- python3.10< 3.10.12-1~22.04.3
- python3.11< 3.11.0~rc1-1~22.04.1~esm1
- python3.4All versions (No fix recorded)
- python3.5< 3.5.2-2ubuntu0~16.04.4~14.04.1+esm1 | < 3.5.2-2ubuntu0~16.04.13+esm12
Debian2 products
- pypy3< 7.3.11+dfsg-2+deb12u2 | < 7.3.13+dfsg-1
- python3.11< 3.11.2-6+deb12u2
Alpine1 product
- python3< 3.9.18-r0 | < 3.10.13-r0 | < 3.11.5-r0
Chainguard1 product
- python-3.9< 3.9.18-r0
Python1 product
- python< 3.8.18 | ≥ 3.9.0, < 3.9.18 | ≥ 3.10.0, < 3.10.13 | ≥ 3.11.0, < 3.11.5
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