What is CVE-2017-1000158?

CVE-2017-1000158 is a critical-severity vulnerability in Python, classified under Integer Overflow or Wraparound. CVSS score: 9.8/10. Published 2017-11-17.

How severe is CVE-2017-1000158?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2017-1000158 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Integer overflow in Python

CVE-2017-1000158

CPython (aka Python) up to 2.7.13 is vulnerable to an integer overflow in the PyString_DecodeEscape function in stringobject.c, resulting in heap-based buffer overflow (and possible arbitrary code execution)

Vulnerability class: Integer Overflow

Published 2017-11-17 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.079 (94.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 95th percentile — 94.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.079 · newest: 0.079 · change: 0.000

Affected products

Python
Debian Linux — versions 7.0, 8.0, 9.0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

lists.debian.org/debian-lts-announce/2017/11/msg00035.html (mailing-list, Mailing List, Third Party Advisory)
lists.debian.org/debian-lts-announce/2018/09/msg00031.html (mailing-list, Mailing List, Third Party Advisory)
bugs.python.org/issue30657 (Patch, Issue Tracking, Vendor Advisory)
www.securitytracker.com/id/1039890 (VDB Entry, Third Party Advisory, vdb-entry)
lists.debian.org/debian-lts-announce/2017/11/msg00036.html (mailing-list, Mailing List, Third Party Advisory)
www.debian.org/security/2018/dsa-4307 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2018/09/msg00030.html (mailing-list, Mailing List, Third Party Advisory)
security.gentoo.org/glsa/201805-02 (vendor-advisory, Third Party Advisory)
security.netapp.com/advisory/ntap-20230216-0001/

Frequently asked questions

What is CVE-2017-1000158?: CVE-2017-1000158 is a critical-severity vulnerability in Python, classified under Integer Overflow or Wraparound. CVSS score: 9.8/10. Published 2017-11-17.
How severe is CVE-2017-1000158?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2017-1000158 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.