Vulnerability · CVE-2018-1061
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.
Published Jun 19, 2018 · catalog updated Oct 15, 2026 · python before versions 2.7.15,
Check if you run it
No confirmed exploitation is on record for CVE-2018-1061. EPSS is 4.92%. Act only if a listed version of python before versions 2.7.15, is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (python before versions 2.7.15,).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 4.92%
- Remediation
- Advisory link
- Affected products
- cpe canonical/ubuntu linux · cpe debian/debian linux · cpe fedoraproject/fedora · cpe python/python · cpe redhat/ansible tower
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe canonical/ubuntu linux12.04
- cpe debian/debian linux8.0
- cpe fedoraproject/fedora28
- cpe python/python3.7.0
- cpe redhat/ansible tower3.3
How to fix CVE-2018-1061
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2018-1061. EPSS is 4.92%. Act only if a listed version of python before versions 2.7.15, is installed.
Which versions are affected?
Compare what you have installed with canonical/ubuntu linux 12.04; debian/debian linux 8.0; redhat/ansible tower 3.3. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-20: Improper Input Validation. EPSS 4.92%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jun 19, 2018 · NIST NVD
Detected
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.
Jun 17, 2026 · NIST NVD
Updated
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.
Oct 15, 2026 · NIST NVD
Updated
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.
Sources
- CVE.orgVulnerability recordCVE-2018-1061
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2018-1061
30-day exploitation probability 4.9%
first.org - NIST NVDVulnerability recordCVE-2018-1061
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.
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 16, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.