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Fencer Vulns
low 2.1

CVE-2026-15310 json

zipfile: bzip2/LZMA/Zstandard members decompress without a max_length bound, defeating chunked-read memory limits

published 2026-08-25 2 mo ago modified 2026-10-05 34 d ago also BIT-libpython-2026-15310 , BIT-python-2026-15310 , BIT-python-min-2026-15310 , EUVD-2026-65519

cvss
2.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

When decompressing crafted zip files using the bzip/LZMA/Zstandard

compressions, Python could use an attacker-controlled size to

pre-allocate memory, possibly resulting in memory exhaustion.

Patch / fix

  • bitnami libpython 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8
  • bitnami python 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8
  • bitnami python-min 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8
  • Python Software Foundation CPython 3.10.22, 3.11.17, 3.12.15, 3.13.16, 3.14.8, 3.15.0rc2
  • python3.11 Debian 12 3.11.2-6+deb12u9
  • python3.14 Debian 14 3.14.7-3
  • python3.15 Debian 14 3.15.0~rc2-1

debian advisories DEBIAN-CVE-2026-15310

  • python3.13 hummingbird 1 3.13.15-1.1.hum1
  • python3.13-idle hummingbird 1 3.13.15-1.1.hum1
  • python3.13-libs hummingbird 1 3.13.15-1.1.hum1
  • python3.13-test hummingbird 1 3.13.15-1.1.hum1
  • python3.13-tkinter hummingbird 1 3.13.15-1.1.hum1
  • python3.13-freethreading hummingbird 1 3.13.15-1.1.hum1
  • python3.12 hummingbird 1 3.12.14-1.1.hum1
  • python3.12-idle hummingbird 1 3.12.14-1.1.hum1

red hat advisories RHSA-2026:65567RHSA-2026:65531RHSA-2026:65525RHSA-2026:65513RHSA-2026:65505

  • python311 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Python 3 15 SP7 3.11.17-150600.3.74.1
  • python311-core SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Python 3 15 SP7 +1 more 3.11.17-150600.3.74.1
  • python313 SLE Module for Python 3 15 SP7 3.13.16-150700.4.61.1
  • python313-core SLE Module for Python 3 15 SP7 3.13.16-150700.4.61.1
  • python311 SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +6 more 3.11.17-150400.9.105.1
  • python311-core SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +6 more 3.11.17-150400.9.105.1
  • python311-documentation SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 3.11.17-150400.9.105.1
  • python3 SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +11 more 3.6.15-150300.10.129.1

suse advisories SUSE-SU-2026:4946-1SUSE-SU-2026:4941-1SUSE-SU-2026:4809-1SUSE-SU-2026:4754-1SUSE-SU-2026:4744-1SUSE-SU-2026:4743-1

  • python312 openSUSE Tumbleweed 3.12.14-2.1
  • python310 openSUSE Tumbleweed 3.10.21-2.1
  • python313 openSUSE Tumbleweed 3.13.15-2.1
  • python311 openSUSE Tumbleweed 3.11.16-2.1
  • python314 openSUSE Tumbleweed 3.14.7-2.1
  • python315 openSUSE Tumbleweed 3.15.0~rc2-1.1

opensuse advisories openSUSE-SU-2026:11975-1openSUSE-SU-2026:11949-1openSUSE-SU-2026:11950-1openSUSE-SU-2026:11886-1openSUSE-SU-2026:11868-1openSUSE-SU-2026:11748-1

  • python3 Alpine 3.23, Alpine 3.22, Alpine 3.21 3.12.15-r0
  • python3 Alpine 3.24 3.14.8-r0

alpine advisories ALPINE-CVE-2026-15310

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python3 Azure Linux 3.0 3.12.15-1

azure linux advisories AZL-98208

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-15310 updated cvss 6.5

python: Python: Denial of Service via crafted zip file memory pre-allocation

  • Red Hat Hardened Images python3 3.14.7-1.1.hum1, python3.14 3.14.7-1.1.hum1, python3.10 3.10.21-1.1.hum1, python3.11 3.11.16-1.2.hum1, python3.12 3.12.14-1.1.hum1, python3.13 3.13.15-1.1.hum1, +27 more
    fixed: vendor fix RHSA-2026:65505
  • Red Hat Hardened Images hi/python
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
bitnami libpython
<3.10.22
>=3.11.0, <3.11.17
>=3.12.0, <3.12.15
>=3.13.0, <3.13.16
>=3.14.0, <3.14.8
3.10.22
3.11.17
3.12.15
3.13.16
3.14.8
bitnami python
<3.10.22
>=3.11.0, <3.11.17
>=3.12.0, <3.12.15
>=3.13.0, <3.13.16
>=3.14.0, <3.14.8
3.10.22
3.11.17
3.12.15
3.13.16
3.14.8
bitnami python-min
<3.10.22
>=3.11.0, <3.11.17
>=3.12.0, <3.12.15
>=3.13.0, <3.13.16
>=3.14.0, <3.14.8
3.10.22
3.11.17
3.12.15
3.13.16
3.14.8

Affected products

  • Python Software Foundation CPython

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.