python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.IS_LINE_JUNK method. An attacker could use this flaw to cause denial of service.
Fix
Patch, vendor advisory and mitigation references on NVD 6
- https://bugs.python.org/issue32981 Vendor Advisory
- https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-6-release-candidate-1 Vendor Advisory
- https://docs.python.org/3.6/whatsnew/changelog.html#python-3-6-5-release-candidate-1 Vendor Advisory
- https://bugs.python.org/issue32981 Vendor Advisory
- https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-6-release-candidate-1 Vendor Advisory
- https://docs.python.org/3.6/whatsnew/changelog.html#python-3-6-5-release-candidate-1 Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · python, debian, redhatNVD modified 2026-10-15 18:17
Affected (CPE criteria) 24
cpe:2.3:a:python:python:*:*:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:alpha1:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:alpha2:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:alpha3:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:alpha4:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:beta1:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:beta2:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:beta3:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:beta4:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:beta5:*:*:*:*:*:*cpe:2.3:a:python:python:3.7.0:rc1:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*cpe:2.3:a:redhat:ansible_tower:3.3:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:*cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
References 42
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- http://www.securitytracker.com/id/1042001 Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHBA-2019:0327 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3041 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3505 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1260
- https://access.redhat.com/errata/RHSA-2019:3725
- https://bugs.python.org/issue32981 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1061 Issue Tracking
- https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-6-release-candidate-1 Vendor Advisory
- https://docs.python.org/3.6/whatsnew/changelog.html#python-3-6-5-release-candidate-1 Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/09/msg00030.html Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/09/msg00031.html Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEEFYBVEXHCK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWYGKO7YU3NJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGOOUIDE4RRB/
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbst03951en_us
- https://usn.ubuntu.com/3817-1/ Third Party Advisory
- https://usn.ubuntu.com/3817-2/ Third Party Advisory
- https://www.debian.org/security/2018/dsa-4306 Third Party Advisory
- https://www.debian.org/security/2018/dsa-4307 Third Party Advisory
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- http://www.securitytracker.com/id/1042001 Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHBA-2019:0327 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3041 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:3505 Third Party Advisory
- https://access.redhat.com/errata/RHSA-2019:1260
- https://access.redhat.com/errata/RHSA-2019:3725
- https://bugs.python.org/issue32981 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1061 Issue Tracking
- https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-6-release-candidate-1 Vendor Advisory
- https://docs.python.org/3.6/whatsnew/changelog.html#python-3-6-5-release-candidate-1 Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/09/msg00030.html Mailing List, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2018/09/msg00031.html Mailing List, Third Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEEFYBVEXHCK/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWYGKO7YU3NJ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGOOUIDE4RRB/
- https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbst03951en_us
- https://usn.ubuntu.com/3817-1/ Third Party Advisory
- https://usn.ubuntu.com/3817-2/ Third Party Advisory
- https://www.debian.org/security/2018/dsa-4306 Third Party Advisory
- https://www.debian.org/security/2018/dsa-4307 Third Party Advisory