CVE-2026-18503

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.12% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 2.1% of scored records. A rank, not a probability.

NVD base score

2.4 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/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

NVD analysis status

Awaiting Analysis. NVD last modified this record on 2026-08-18.

Red Hat severity

Low. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-08-10 13:45Z25 DAYS AGO

Last updated

2026-08-13 00:28Z22 DAYS AGO

Reserved

2026-07-31

Assigning CNA

PSF

Record state

PUBLISHED

Severity

Low (CVSS 2.4)

CNA CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

Weaknesses

• CWE-1176Inefficient CPU ComputationClass
• CWE-1333Inefficient Regular Expression ComplexityBase

Data version

5.2

Document digest

8b398d55f52fccc884272af845c69f4325eecc58ea02879dde974573a5df8984

• mail.python.orghttps://mail.python.org/archives/list/security-announce@python.org/thread/KQ7NBMCPAZJHRROQXJQE4GMXGLD5KHBS/vendor-advisory
• github.comhttps://github.com/python/cpython/pull/153694patch
• github.comhttps://github.com/python/cpython/issues/98820issue-tracking
• github.comhttps://github.com/python/cpython/commit/063d4555c94ef412c731527dbf30193327f2ee82patch
• github.comhttps://github.com/python/cpython/commit/476fb09cdb0d73e645849d98c610e7e5697ce7c9patch
• github.comhttps://github.com/python/cpython/commit/89f29c760c02774b099ddd6863268eb13fa3946apatch
• github.comhttps://github.com/python/cpython/commit/b30c7fa9edd921a118f286e9f90f560777fa693bpatch
• github.comhttps://github.com/python/cpython/commit/b09a67a20c464f8288c9f9a6b9c7082a74560024patch
• github.comhttps://github.com/python/cpython/commit/fd78b565d7c326f96ae903ab945b47f35d829cf4patch