CVE-2026-9669

HIGHPre-NVD 8.28.2
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (37th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-35202 (ENISA EUVD) · GHSA-8jvr-397x-xqh9 (GitHub Security Advisories)Source: ENISA EUVD

8.2EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.2Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
8.2
EG Score
8.2HIGHmedium confidence
EG Risk
37
EG Risk 37/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity82% × 45%
Impact severity (EG Severity): CVSS 8.2 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
37th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.2): severity, escalated by confirmed exploitation. This CVE's 8.2 is its impact severity (EG Severity), not escalated.

EG Severity
8.2 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

June 8, 2026

Last Modified

August 13, 2026

Advisory Details (4)

Auto-updated Jun 9, 2026
Patch available. Sources: github_pr.
Web page

oss-security - [CVE-2026-9669] CPython: bz2.BZ2Decompressor reuse after error can cause a stack buffer overflow

http://www.openwall.com/lists/oss-security/2026/06/08/17
Web page

Mailman 3 [CVE-2026-9669] bz2.BZ2Decompressor reuse after error can cause a stack buffer overflow - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/DBJZETMGUIFK7DVUWMOXHD3Z6IX2QPSX/
GitHub pull request

gh-150599: Prevent bz2 decompressor reuse after errors

Fix merged in python/cpython PR #150600 on 2026-06-07 — awaiting tagged release

https://github.com/python/cpython/pull/150600
Web page

Stack buffer overflow in bz2 when reusing BZ2Decompressor after error · Issue #150599 · python/cpython · GitHub

https://github.com/python/cpython/issues/150599

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntupython3.14-venv (3.14.4-1ubuntu0.1) @ resolute2026-10-27ubuntu
redhatpython3-11-main-3.11.16-1.4.hum12026-09-16redhat
redhatpython3-12-main-3.12.14-1.3.hum12026-09-16redhat
redhatpython3-13-main-3.13.15-1.3.hum12026-09-16redhat
redhatpython3-10-main-3.10.21-1.3.hum12026-09-16redhat
redhatpython3-14-main-3.14.7-1.2.hum12026-09-15redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(6 across 5 ecosystems)
Debian:14(2)
PackageVulnerable rangeFix by version rangeDependents
python3.133.13.11-1 ... 3.13.9-1 (7 versions)
  • every version up to 3.13.14-1: fixed in 3.13.14-1
—
python3.143.14.0-1 ... 3.14.5~rc1-1 (23 versions)
  • every version up to 3.14.6-1: fixed in 3.14.6-1
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.14.7-r0: fixed in 3.14.7-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
python3.93.9.10-1 ... 3.9.9-4 (29 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
python3.113.11.2-6 ... 3.11.2-6+deb12u8 (9 versions)
  • every version up to 3.11.2-6+deb12u9: fixed in 3.11.2-6+deb12u9
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
python3.133.13.5-2, 3.13.5-2+deb13u1, 3.13.5-2+deb13u2
  • every version up to 3.13.5-2+deb13u3: fixed in 3.13.5-2+deb13u3
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(1)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 11× in last 7d / 46× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 99 of 363 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 264 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-27 12:23 UTCEG score recompute
  6. 2026-10-27 12:23 UTCVendor advisory
  7. 2026-10-27 12:23 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  8. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  9. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  10. 2026-10-25 13:48 UTCEG score recompute
  11. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-23 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  16. 2026-10-19 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  17. 2026-10-19 13:51 UTCEG score recompute
  18. 2026-10-19 13:51 UTCVendor advisory
  19. 2026-10-19 13:51 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  20. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-10-18 02:57 UTCEG score recompute
  22. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  24. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
Show 74 more
  1. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  2. 2026-10-13 04:06 UTCEG score recompute
  3. 2026-10-13 04:06 UTCVendor advisory
  4. 2026-10-13 04:06 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  5. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-10-12 14:40 UTCEG score recompute
  7. 2026-10-11 19:11 UTCEG score recompute
  8. 2026-10-11 16:27 UTCEG score recompute
  9. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-10-11 13:39 UTCEG score recompute
  11. 2026-10-10 20:01 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  14. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  15. 2026-10-06 15:19 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  16. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  17. 2026-10-04 23:23 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  18. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  19. 2026-10-03 10:09 UTCOSV refresh
  20. 2026-10-02 17:57 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  21. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.6% · 47th percentile
  22. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  23. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  24. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  25. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  26. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  27. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 46th percentile
  28. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  29. 2026-09-22 16:01 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  30. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  31. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  32. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  33. 2026-09-17 19:32 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  34. 2026-09-16 14:09 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  35. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  36. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  37. 2026-09-14 04:48 UTCEG score recompute
  38. 2026-09-14 04:48 UTCVendor advisory
  39. 2026-09-14 04:48 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  40. 2026-09-13 16:48 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  41. 2026-09-12 15:02 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  42. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  43. 2026-09-11 09:38 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  44. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  45. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.7% · 50th percentile
  46. 2026-09-06 13:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  47. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  48. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  49. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  50. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  51. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  52. 2026-08-31 01:36 UTCEG score recompute
  53. 2026-08-31 01:36 UTCVendor advisory
  54. 2026-08-31 01:36 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  55. 2026-08-30 19:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  56. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  57. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  58. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  59. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  60. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  61. 2026-08-25 01:14 UTCEG score recompute
  62. 2026-08-25 01:14 UTCVendor advisory
  63. 2026-08-25 01:14 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  64. 2026-08-24 14:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  65. 2026-08-24 00:05 UTCVendor advisory
  66. 2026-08-24 00:05 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  67. 2026-08-23 11:41 UTCEG score recompute
  68. 2026-08-23 11:41 UTCVendor advisory
  69. 2026-08-23 11:41 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  70. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  71. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  72. 2026-08-21 22:52 UTCVendor advisory
  73. 2026-08-21 22:52 UTCGHSA enrichmentGHSA-8jvr-397x-xqh9 · GitHub severity HIGH
  74. 2026-08-21 10:29 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-9669?
CVE-2026-9669 is a high-severity vulnerability; its CVE record was published on June 8, 2026. 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.…
When was the CVE record for CVE-2026-9669 published?
The CVE record for CVE-2026-9669 was published on June 8, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of August 13, 2026; the record at its source may have been updated since.
Is CVE-2026-9669 actively exploited?
CVE-2026-9669 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-9669?
CVE-2026-9669 has a CVSS base score of 8.2 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-9669?
A fix for CVE-2026-9669 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-9669 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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