CVE-2025-4516

20

FAUCET Score

CVE-2025-4516 is a medium-severity vulnerability affecting CPython when using bytes.decode("unicode_escape", error="ignore|replace"). It allows for a denial of service (VA:H) with a CVSS score of 5.9, but only impacts systems not using the "unicode_escape" encoding or an error handler. The attack vector is local (AV:L) with high attack complexity (AC:H), and there are no known public exploits, Metasploit modules, or Nuclei templates available. While there is limited community discussion and media coverage, the vulnerability is not currently on CISA's KEV or Hot List.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		>= 0, < 3.10.18CPE match	cpe:2.3:a:python:python::::::::
		>= 3.11.0, < 3.11.13CPE match	cpe:2.3:a:python:python::::::::
		>= 3.12.0, < 3.12.11CPE match	cpe:2.3:a:python:python::::::::
		>= 3.13.0, < 3.13.4CPE match	cpe:2.3:a:python:python::::::::

CVSS Data

CVSS version used by this source: 4.0

5.9MEDIUM

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

Attack Vector

LOCAL

Attack Complexity

HIGH

Attack Requirements

PRESENT

Privileges Required

NONE

User Interaction

NONE

VS Confidentiality

NONE

VS Integrity

NONE

VS Availability

HIGH

SS Confidentiality

NONE

SS Integrity

NONE

SS Availability

NONE

Exploit Maturity

NOT_DEFINED

CvssVersion

4.0

Exploit Intelligence

EPSS Score

0.18%

Probability of exploitation in next 30 days

EPSS Percentile

7.5%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0018 is in the 4th percentile among its peer group of 1,595 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (34)

autodeskpatch availablevia llm_extracted

freepbxpatch availablevia llm_extracted

honeywellpatch availablevia llm_extracted

microsoftpatch availablevia msrc

Product: azl3 python3 3.12.9-2 on Azure Linux 3.0Fixed in: 3.12.9-2

microsoftpatch availablevia msrc

Product: cbl2 python3 3.9.19-14 on CBL Mariner 2.0Fixed in: 3.9.19-14

microsoftpatch availablevia msrc

Product: cbl2 python3 3.9.19-13 on CBL Mariner 2.0Fixed in: 3.9.19-14

microsoftpatch availablevia msrc

Product: 19533-16823Fixed in: 3.9.19-14

microsoftpatch availablevia msrc

Product: 19681-17086Fixed in: 3.9.19-14

microsoftpatch availablevia msrc

Product: 19601-17084Fixed in: 3.12.9-2

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python39-devel:3.9-8100020251126112422.d47b87a4

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python39:3.9-8100020251126112422.d47b87a4

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-aws-nvidia-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-azure-amd-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-azure-nvidia-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-gcp-nvidia-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: python3.9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-nvidia-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/granite-3.1-8b-lab-v2.1

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/granite-3.1-8b-starter-v2.1

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/instructlab-amd-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/instructlab-nvidia-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/modelcar-granite-3-1-8b-lab-v2-1

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/modelcar-granite-3-1-8b-starter-v2-1

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-intel-rhel9

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 10Fixed in: python3.12

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: python

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: python3

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python3

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python3.11

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python3.12

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: python36:3.6/python36

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: python3.11

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux 9Fixed in: python3.12

redhatvendor investigatingvia redhat_api

Product: Red Hat Enterprise Linux AI (RHEL AI)Fixed in: rhelai1/bootc-amd-rhel9

Vendor Advisories (5)

honeywellllm-honeywell-c82b5cfda9df97a3CRITICAL

HP ThinPro 8.1 SP8 Security Updates

autodeskllm-autodesk-c365b674a2ff5a3aCRITICAL

HP ThinPro 8.1 SP8 Security Updates

freepbxllm-freepbx-e54908c7967265f6CRITICAL

HP ThinPro 8.1 SP8 Security Updates

redhatCVE-2025-4516Moderate

cpython: python: CPython DecodeError Handling Vulnerability

microsoft2025-May/CVE-2025-4516Moderate

Use-after-free in "unicode_escape" decoder with error handler

References

openwall.com / lists/oss-security/2025/05/16/4

openwall.com / lists/oss-security/2025/05/19/1

github.com / python/cpython/commit/4398b788ffc1f954a2c552da285477d42a571292

github.com / python/cpython/commit/6279eb8c076d89d3739a6edb393e43c7929b429d

github.com / python/cpython/commit/69b4387f78f413e8c47572a85b3478c47eba8142

github.com / python/cpython/commit/73b3040f592436385007918887b7e2132aa8431f

github.com / python/cpython/commit/8d35fd1b34935221aff23a1ab69a429dd156be77

github.com / python/cpython/commit/9f69a58623bd01349a18ba0c7a9cb1dad6a51e8e

github.com / python/cpython/commit/ab9893c40609935e0d40a6d2a7307ea51aec598b

github.com / python/cpython/issues/133767

github.com / python/cpython/pull/129648

mail.python.org / archives/list/[email protected]/thread/L75IPBBTSCYEF56I2M4KIW353BB3AY74