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VulnerabilityPublished Updated

CVE-2025-11468: Python Software Foundation CPython · CRLF Injection

Affects Python Software Foundation CPythonSource CVE Database V5

0

Not known to be exploited · CVSS 5.7 Medium · fixed in 3.15.0a6 : update Python Software Foundation CPython when convenient.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 4.0 base score
5.7Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 3.15.0a6, 3.14.3, 3.13.12 +3
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 20 Jan 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Python Software FoundationCPythonAffected
  • >=3.15.0a1 <3.15.0a6
Fixed in
  • 3.15.0a6
Python Software FoundationCPythonAffected
  • >=3.14.0 <3.14.3
Fixed in
  • 3.14.3
Python Software FoundationCPythonAffected
  • >=3.13.0 <3.13.12
Fixed in
  • 3.13.12
Python Software FoundationCPythonAffected
  • >=3.12.0 <3.12.13
Fixed in
  • 3.12.13
Python Software FoundationCPythonAffected
  • >=3.11.0 <3.11.15
Fixed in
  • 3.11.15
Python Software FoundationCPythonAffected
  • <3.10.20
Fixed in
  • 3.10.20

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Organizations should monitor for official patches from the Python Software Foundation and apply them promptly once released. If you cannot patch yet, developers should implement strict input validation and sanitization on all user-controlled email address fields to prevent injection of unfoldable characters or malicious payloads. Employing robust email header construction libraries that correctly handle folding and escaping can mitigate risks. Additionally, deploying email security gateways and filters that detect anomalous or malformed headers can provide a secondary defense layer. Restricting privileges for processes handling email generation reduces the attack surface. Conducting code reviews focused on email header handling and incorporating fuzz testing for header parsing logic can help identify similar issues proactively. Finally, educating developers about secure email handling practices and the risks of header injection is essential.

Description

When folding a long comment in an email header containing exclusively unfoldable characters, the parenthesis would not be preserved. This could be used for injecting headers into email messages where addresses are user-controlled and not sanitized.

References

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