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Public proof of conceptFix available

CVE-2016-5636

A public proof of concept exists; no exploitation attested.

  • Published2016-09-02
  • WeaknessCWE-190

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Integer overflow in the get_data function in zipimport.c in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 allows remote attackers to have unspecified impact via a negative data size value, which triggers a heap-based buffer overflow.

Timeline

dates in UTC
  1. 2016-09-0214:59CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub
  3. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-11-04 03:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-5636?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-5636?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Python
BranchAffectedFixed in
3.0= 3.0no fix published
3.0= 3.0.1no fix published
3.1= 3.1.0no fix published
3.1= 3.1.1no fix published
3.1= 3.1.2no fix published
3.1= 3.1.3no fix published
3.1= 3.1.4no fix published
3.1= 3.1.5no fix published
3.2= 3.2.0no fix published
3.2= 3.2.1no fix published
3.2= 3.2.2no fix published
3.2= 3.2.3no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • pythonTuxCare:OracleLinux:6all versions · fixed in 2.6.6-70.el6.tuxcare.els15and 5 other packages
  • pythonTuxCare:CentOS:6all versions · fixed in 2.6.6-70.el6.tuxcare.els15and 5 other packages
  • pythonSUSE:Linux Enterprise Software Development Kit 11 SP4all versions · fixed in 2.6.9-40.15.1and 1 other package
  • pythonSUSE:Linux Enterprise Server for SAP Applications 12 SP1all versions · fixed in 2.7.9-24.1
  • pythonSUSE:Linux Enterprise Server for SAP Applications 11 SP4all versions · fixed in 2.6.9-40.15.1and 1 other package
  • pythonSUSE:Linux Enterprise Server 12-LTSSall versions · fixed in 2.7.9-16.7.1
  • pythonSUSE:Linux Enterprise Server 12 SP1all versions · fixed in 2.7.9-24.1
  • pythonSUSE:Linux Enterprise Server 11 SP4all versions · fixed in 2.6.9-40.15.1and 1 other package

60 more package ranges on OSV.dev

Full record on NVD

Fix

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedinsuyun/CVE-2016-5636
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVSS 3.09.8read 2026-10-23
  • NVDCVSS 2.010read 2026-10-23
  • NVDweakness (CWE)CWE-190read 2026-10-23
  • FIRST EPSSEPSS score25.5 %read 2026-11-03
  • PoC-in-GitHubproof of concept1read 2026-11-03
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2016-09-02
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2016-5636?

Integer overflow in the get_data function in zipimport.c in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 allows remote attackers to have unspecified impact via a negative data size value, which triggers a heap-based buffer overflow.

Is CVE-2016-5636 actively exploited?

Active exploitation of CVE-2016-5636 has not been confirmed. Its EPSS score was 25.5% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-5636?

CVE-2016-5636 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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