Out-of-Bounds Write in python (CVE-2026-3298)

Summary

Out-of-bounds write in python (CVE-2026-3298). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 3.14.5 or later.

Original description

The description as published by the source.

The method "sock_recvfrom_into()" of "asyncio.ProacterEventLoop" (Windows only) was missing a boundary check for the data buffer when using nbytes parameter. This allowed for an out-of-bounds buffer write if data was larger than the buffer size. Non-Windows platforms are not affected.

Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-3298 has been found in python.
Risk of unauthorized operations or information disclosure.
What to do: upgrade python to 3.14.5 or later.
If unsure, ask your IT team or search "python CVE-2026-3298" on the vendor's site.

CVE-2026-3298 (python) — CWE-787
Patched: 3.14.5 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Out-of-bounds write (CWE-787) exists in python.

📍 Affected scope

Check the vendor advisory for the affected versions of python.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 3.14.5.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'python' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'python' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で python を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade python to 3.14.5
```
ステージング環境で 3.14.5 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Bitnami python

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.11.16"},{"introduced":"3.12.0"},{"fixed":"3.12.14"},{"introduced":"3.13.0"},{"fixed":"3.13.14"},{"introduced":"3.14.0"},{"fixed":"3.14.5"}]}]

Bitnami libpython

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.11.16"},{"introduced":"3.12.0"},{"fixed":"3.12.14"},{"introduced":"3.13.0"},{"fixed":"3.13.14"},{"introduced":"3.14.0"},{"fixed":"3.14.5"}]}]

Bitnami python-min

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"3.11.16"},{"introduced":"3.12.0"},{"fixed":"3.12.14"},{"introduced":"3.13.0"},{"fixed":"3.13.14"},{"introduced":"3.14.0"},{"fixed":"3.14.5"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Ubuntu UBUNTU-CVE-2026-3298 python2.7

References

advisory mail.python.org
advisory nvd.nist.gov
advisory github.com
package github.com
patch github.com
patch github.com
patch github.com
patch github.com
patch github.com
patch github.com
report github.com
web mail.python.org
web github.com