CVE-2026-9669
CVE-2026-9669 is a high-severity vulnerability with a CVSS 4.0 base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.
Key facts
- Severity: High (CVSS 4.0 base score 8.2)
- EPSS exploit prediction: 0% (35th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-35202
- Weakness: CWE-121
- Published:
- Last modified:
Description
bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.
Frequently asked questions
- What is CVE-2026-9669?
- bz2.BZ2Decompressor objects could be reused after a decompression error. If an application caught the resulting OSError and retried with the same decompressor, crafted input could cause the decompressor to resume from an invalid internal state and perform out-of-bounds writes to a stack buffer. This could crash the process when processing untrusted data.
- How severe is CVE-2026-9669?
- CVE-2026-9669 has a CVSS 4.0 base score of 8.2, rated high severity.
- Is CVE-2026-9669 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-9669?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-9669 have an EU (EUVD) identifier?
- Yes. CVE-2026-9669 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-35202.
- When was CVE-2026-9669 published?
- CVE-2026-9669 was published on 2026-06-08 and last updated on 2026-07-07.
References
- https://github.com/python/cpython/commit/157a5df8cb5d82b33f918a7489e72ce95ceb12b6
- https://github.com/python/cpython/commit/5755d0f083949ff3c5bf3a37e673e24e306b036e
- https://github.com/python/cpython/commit/619a12b2e545391dc436b3af79dda22337382a6f
- https://github.com/python/cpython/commit/938ec030e90c5e53f1faac6fab1643f14e4f4a79
- https://github.com/python/cpython/commit/d3ca26983dfbccdf609f24ff5877dc3118e4702d
- https://github.com/python/cpython/issues/150599
- https://github.com/python/cpython/pull/150600
- https://mail.python.org/archives/list/[email protected]/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/
- http://www.openwall.com/lists/oss-security/2026/06/08/17
Other CWE-121 (Stack-based Buffer Overflow) vulnerabilities
- CVE-2026-12848 — Critical (CVSS 10.0): GV-I/O Box 4E is a smart embedded device with 4 input and 4 relays output that can be controlled over Ethernet and…
- CVE-2026-12847 — Critical (CVSS 10.0): GV-I/O Box 4E is a smart embedded device with 4 input and 4 relays output that can be controlled over Ethernet and…
- CVE-2026-12846 — Critical (CVSS 10.0): GV-I/O Box 4E is a smart embedded device with 4 input and 4 relays output that can be controlled over Ethernet and…
- CVE-2026-12485 — Critical (CVSS 10.0): GV-I/O Box 4E is a smart embedded device with 4 input and 4 relays output that can be controlled over Ethernet and…
- CVE-2026-37541 — Critical (CVSS 10.0): Buffer overflow vulnerability in Open Vehicle Monitoring System 3 (OVMS3) 3.3.005. In canformat_gvret.cpp, the length…
- CVE-2026-42996 — Critical (CVSS 10.0): JS8Call through 2.3.1 and JS8Call-improved before 3.0 have a stack-based buffer overflow via a radio transmission of…
Browse all CWE-121 (Stack-based Buffer Overflow) vulnerabilities →