CVE-2026-0864

CVE-2026-0864 is a medium-severity vulnerability in Python with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-74.

Key facts

• Severity: Medium (CVSS 3.x base score 5.5)
• CVSS v4: 4.1
• EPSS exploit prediction: 0% (2nd percentile)
• Actively exploited: Not listed in CISA KEV
• EU (EUVD) id: EUVD-2026-38554
• Weakness: CWE-74
• Affected product: Python
• Published: 2026-06-23
• Last modified: 2026-08-18

Description

When using the "configparser" module to write configuration files containing multi-line text values with carriage return characters (\r) the resulting file could be injected with unexpected keys and values if the attacker controls the written value.

Frequently asked questions

What is CVE-2026-0864?

When using the "configparser" module to write configuration files containing multi-line text values with carriage return characters (\r) the resulting file could be injected with unexpected keys and values if the attacker controls the written value.

How severe is CVE-2026-0864?

CVE-2026-0864 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-0864 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-0864?

CVE-2026-0864 primarily affects Python. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-0864?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-0864 have an EU (EUVD) identifier?

Yes. CVE-2026-0864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38554.

When was CVE-2026-0864 published?

CVE-2026-0864 was published on 2026-06-23 and last updated on 2026-08-18.

References

• https://github.com/python/cpython/commit/0adb386f6e68eb2e73d32e19f235d012df009528
• https://github.com/python/cpython/commit/12dcbd74d3563016a8cb8c47e4898889f34f74dd
• https://github.com/python/cpython/commit/274de100bbf4345bd0c23ef5b446722e9e636908
• https://github.com/python/cpython/commit/5858e42c539dac8394636a6e9b30472b8994851f
• https://github.com/python/cpython/commit/71f2e02a52d47417a6fd69f456346cd8aa7aca98
• https://github.com/python/cpython/commit/aaf850fd333cd89e9aada03d92aaa788a6cb1bb8
• https://github.com/python/cpython/commit/db4a157c790479710a1a840d7937c5c815a6f8b6
• https://github.com/python/cpython/issues/143927
• https://github.com/python/cpython/pull/151559
• https://mail.python.org/archives/list/[email protected]/thread/CV4NE6AFCRJL7XQOHX7J5TSDHUWVWGJS/

Affected products (12)

• cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:alpha8:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:beta1:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:beta2:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.15.0:beta3:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

• 207.180.210.142 (ipv4-addr)
• 178.128.122.173 (ipv4-addr)
• 158.94.211.199 (ipv4-addr)
• 157.245.72.120 (ipv4-addr)
• 154.217.251.226 (ipv4-addr)
• 45.234.93.65 (ipv4-addr)
• 94.156.237.31 (ipv4-addr)
• 120.28.222.139 (ipv4-addr)