8.9

CVE-2026-44432: urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API

Modified
AliasesGHSA-mf9v-mfxr-j63jPYSEC-2026-142RHSA-2026:24000
Published 13-05-2026Last modified 10-09-2026

Vulnerability summary

CVE-2026-44432 is a high (CVSS 8.9) vulnerability in python urllib3. EPSS estimates a 0.68% chance of exploitation in the next 30 days, higher than 52.4% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 8.9 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
8.9/10
010
High · v4.0 (CVE.org)
EPSS score
0.68%
0%100%
Low · -0.20 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 19 · Related 2
RHSA-2026:15862RHSA-2026:22934RHSA-2026:24009RHSA-2026:24069RHSA-2026:25039RHSA-2026:25143

Timeline

  1. 13-05-2026
    PublishedVulnerability first disclosed.
  2. 10-09-2026
    Last modifiedVulnerability information updated.

Description

urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was called after the response had been read and decompressed partially (compression algorithm did not matter here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This could result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.

CVSS metrics

11 scores · 8 sources · 2 versions

EPSS trend

Probability

0.68%

Chance of exploitation in the next 30 days

Percentile

52%

Versus all other CVEs

30-day change

Decrease -0.20 pp

From 0.88% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard162 products
  • airflow-2< 2.11.2-r26
  • airflow-3< 3.2.1-r4
  • airflow-core-2< 2.11.2-r11
  • airflow-core-3< 3.2.1-r1
  • ansible-operator< 1.42.2-r7 | < 1.42.3-r1
Wolfi38 products
  • airflow-3< 3.2.1-r4
  • aws-cli-2< 2.34.55-r0
  • az< 2.86.0-r0
  • confluent-docker-utils< 0.0.172-r0
  • dask-kubernetes< 2026.3.0-r5

2 vendors · 200 products · Showing 200 of 253

References

77 links
Show all 77 references