StackPrism

PyPI package

urllib3 2.6.3 vulnerabilities, and the version that fixes all of them

urllib3 2.6.3 has 5 known vulnerabilities (4 rated high or critical); 2.8.0 fixes all of them.

PyPI (opens in a new tab) describes it as “HTTP library with thread-safe connection pooling, file post, and more.”

Known vulnerabilities
5
4 rated high or critical
Released
Jan 7, 2026
Latest is 2.8.0
Licence
MIT
OpenSSF Scorecard
8.6/10
urllib3/urllib3 (opens in a new tab)
Dependencies
None
Resolved by deps.dev

What to upgrade to

2.8.0 is the closest release with no known vulnerabilities.

  • 2.8.0Upgrade to this

    Fixes all 5 known vulnerabilities and the newest 2.x release and the latest release. Released Sep 15, 2026.

    No known vulnerabilities

2.8.0 came out on Sep 15, 2026. A coding agent trained before then doesn’t know it exists, so it may suggest an older release. AI knowledge cutoff dates

Hand the fix to your coding agent

One task with the upgrade, the file to change and why. Paste it into Claude Code, Cursor or Codex.

Findings

Every advisory for urllib3 2.6.3

Known exploited first (CISA KEV), then by how likely they are to be exploited (FIRST EPSS), then by severity. Each id links to its OSV.dev record.

  1. CriticalCVE-2026-44432 on OSV.dev (opens in a new tab)GHSA-mf9v-mfxr-j63jEPSS: top 42%

    urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API

    Fixed in 2.7.0. Published May 11, 2026.

  2. CriticalCVE-2026-44431 on OSV.dev (opens in a new tab)GHSA-qccp-gfcp-xxvcEPSS: top 75%

    urllib3: Sensitive headers forwarded across origins in proxied low-level redirects

    Fixed in 2.7.0. Published May 11, 2026.

  3. CriticalCVE-2026-97689 on OSV.dev (opens in a new tab)GHSA-vxq7-64xx-v4gwEPSS: top 75%

    urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory

    Fixed in 2.8.0. Published Sep 30, 2026.

  4. WarningCVE-2026-97688 on OSV.dev (opens in a new tab)GHSA-gh4c-6fx4-qh6gEPSS: top 80%

    urllib3: Chunked Deflate streaming can enter an infinite loop

    Fixed in 2.8.0. Published Sep 30, 2026.

  5. CriticalCVE-2026-97687 on OSV.dev (opens in a new tab)GHSA-8988-9cw3-xx77EPSS: top 91%

    urllib3: HTTPS proxy TLS configuration may be ignored or overridden

    Fixed in 2.8.0. Published Sep 30, 2026.

Is urllib3 the only one?

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How this page is checked

StackPrism asks OSV.dev which advisories affect exactly urllib3 2.6.3, merges duplicates filed under several ids, and ranks them with CISA’s Known Exploited Vulnerabilities list and FIRST EPSS. Release dates and deprecation come from deps.dev and PyPI. No AI writes this page: every sentence comes from that data, refreshed every few hours.

Last checked against PyPI, OSV.dev, deps.dev, CISA KEV and FIRST EPSS.