CVE-2025-4516 (GCVE-0-2025-4516)

Vulnerability from cvelistv5 – Published: 2025-05-15 13:29 – Updated: 2026-04-21 20:16
VLAI
Title
Use-after-free in "unicode_escape" decoder with error handler
Summary
There is an issue in CPython when using `bytes.decode("unicode_escape", error="ignore|replace")`. If you are not using the "unicode_escape" encoding or an error handler your usage is not affected. To work-around this issue you may stop using the error= handler and instead wrap the bytes.decode() call in a try-except catching the DecodeError.
Severity
5.9 (Medium)
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
Assigner
PSF
References
Impacted products
Vendor Product Version
Python Software Foundation CPython Affected: 0 , < 3.10.18 (python)
Affected: 3.11.0 , < 3.11.13 (python)
Affected: 3.12.0 , < 3.12.11 (python)
Affected: 3.13.0 , < 3.13.4 (python)
Affected: 3.14.0a1 , < 3.14.0b2 (python)
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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