- 5.9MediumCVSS base score
- 0.22%Exploitation in 30 daysEPSS · top 87% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By PSF
- 6 days later
· 6 days later
Published
- 15 months later
· 15 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| PSFCNA (assigner) | 4.0 | Medium5.9 | 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 |
| NVDNVD · Deferred | 4.0 | Medium5.9 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.22% · top 87% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Affected products
Python Software Foundation · CPython
- affected < 3.9.23
- affected 3.10.0 – < 3.10.18
- affected 3.11.0 – < 3.11.13
- affected 3.12.0 – < 3.12.11
- affected 3.13.0 – < 3.13.4
- affected 3.14.0a1 – < 3.14.0b2
References
12
- https://github.com/python/cpython/issues/133767 (opens in a new tab)issue-tracking
- https://github.com/python/cpython/pull/129648 (opens in a new tab)patch
- https://mail.python.org/archives/list/[email protected]/thread/L75IPBBTSCYEF56I2M4KIW353BB3AY74/ (opens in a new tab)vendor-advisory
- https://github.com/python/cpython/commit/69b4387f78f413e8c47572a85b3478c47eba8142 (opens in a new tab)patch
- https://github.com/python/cpython/commit/9f69a58623bd01349a18ba0c7a9cb1dad6a51e8e (opens in a new tab)patch
- https://github.com/python/cpython/commit/4398b788ffc1f954a2c552da285477d42a571292 (opens in a new tab)patch
- https://github.com/python/cpython/commit/6279eb8c076d89d3739a6edb393e43c7929b429d (opens in a new tab)patch
- https://github.com/python/cpython/commit/73b3040f592436385007918887b7e2132aa8431f (opens in a new tab)patch
- https://github.com/python/cpython/commit/8d35fd1b34935221aff23a1ab69a429dd156be77 (opens in a new tab)patch
- https://github.com/python/cpython/commit/ab9893c40609935e0d40a6d2a7307ea51aec598b (opens in a new tab)patch
- http://www.openwall.com/lists/oss-security/2025/05/16/4 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2025/05/19/1 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-15156 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-4516)Record last updated .