Public proof of conceptFix available

CVE-2018-25032

Q: Is CVE-2018-25032 actively exploited?

A proof-of-concept exploit exists for CVE-2018-25032, but active exploitation has not been confirmed at this time.

Q: What is the CVSS score for CVE-2018-25032?

CVE-2018-25032 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

A public proof of concept exists; no exploitation attested.

Published2022-03-25
Fixed in1.2.12
WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

zlib before 1.2.12 allows memory corruption when deflating (i.e., when compressing) if the input has many distant matches.

Timeline

dates in UTC

2022-03-2509:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-27 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-25032?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-25032?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Zlib

Branch	Affected	Fixed in	Source
1.2	≥ 1.2.2.2, < 1.2.12	1.2.12	NVD

Azul zulu

Branch	Affected	Fixed in	Source
6.45	= 6.45	no fix published	NVD
7.52	= 7.52	no fix published	NVD
8.60	= 8.60	no fix published	NVD
11.54	= 11.54	no fix published	NVD
13.46	= 13.46	no fix published	NVD
15.38	= 15.38	no fix published	NVD
17.32	= 17.32	no fix published	NVD

MariaDB

Branch	Affected	Fixed in	Source
10.9	≥ 10.9.0, < 10.9.2	10.9.2	NVD
10.8	≥ 10.8.0, < 10.8.4	10.8.4	NVD
10.7	≥ 10.7.0, < 10.7.5	10.7.5	NVD
10.6	≥ 10.6.0, < 10.6.9	10.6.9	NVD
10.5	≥ 10.5.0, < 10.5.17	10.5.17	NVD
10.4	≥ 10.4.0, < 10.4.26	10.4.26	NVD
10.3	≥ 10.3.0, < 10.3.36	10.3.36	NVD

24 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

mingw32-zlibAlmaLinux:9all versions · fixed in 1.2.12-2.el9and 3 other packages
mingw32-zlibAlmaLinux:8all versions · fixed in 1.2.8-10.el8and 3 other packages
rsyncAlmaLinux:8all versions · fixed in 3.1.3-14.el8and 1 other package
zlibAlmaLinux:8all versions · fixed in 1.2.11-18.el8_5and 2 other packages

Vendor advisories

CVE-2018-25032 Red Hat Product Security467 products fixed
zlib: A flaw found in zlib when compressing (not decompressing) certain inputs
ICSA-26-202-06 CISA1 known affected
Siemens CADRA
CADRA < V2511
SSA-470355 Siemens ProductCERT1 known affected
SSA-470355: Zlib and Foxit Vulnerabilities in CADRA
CADRA < V2511
ICSA-23-348-10 CISA5 known affected
Siemens SIMATIC S7-1500
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) · +2 more
SSA-398330 Siemens ProductCERT5 known affected
SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.0 < V3.1.5 · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.0 < V3.1.5 · +2 more
ICSA-23-166-12 CISA1 known affected
Siemens SINAMICS Medium Voltage Products
SINAMICS PERFECT HARMONY GH180 6SR5

27 more advisories

Full record on NVD

Fix

Update Zlib to 1.2.12
Vendor fix CISA ICSA-26-202-06 · 1 productUpdate to V2511 or later version
Vendor fix Siemens ProductCERT SSA-470355 · 1 productUpdate to V2511 or later version
Vendor fix Siemens ProductCERT SSA-398330 · 1 productUpdate to V3.1.5 or later version
Vendor fix CISA ICSA-23-348-10 · 5 productsUpdate to V3.1.5 or later version
Vendor fix Siemens ProductCERT SSA-942865 · 1 productUpdate the firmware of the integrated SCALANCE S615 device to V7.2 or later version
Vendor fix CISA ICSA-23-166-12 · 1 productUpdate the firmware of the integrated SCALANCE S615 device to V7.2 or later version

Advisories and patches

Detection

read 2026-10-27 00:21 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 3 repositories, unverifiedTrinadh465/external_zlib_4.4_CVE-2018-25032Satheesh575555/external_zlib-1.2.7_CVE-2018-25032Trinadh465/external_zlib_AOSP10_r33_CVE-2018-25032

Sources

CISA-ADPSSVC decisionpoc2025-04-23
OpenCVESSVC decisionpoc—
CISA-ADPCVSS 3.17.52025-05-05
NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
CISA-ADPweakness (CWE)CWE-7872025-05-05
NVDweakness (CWE)CWE-787read 2026-10-23
FIRST EPSSEPSS score51.7 %read 2026-10-27
PoC-in-GitHubproof of concept3read 2026-10-27
OSVaffected packages—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2022-03-25
Last Modified: 2026-10-14
NVD status: Modified

Frequently asked questions

What is CVE-2018-25032?

zlib before 1.2.12 allows memory corruption when deflating (i.e., when compressing) if the input has many distant matches.

Is CVE-2018-25032 actively exploited?

A proof-of-concept exploit exists for CVE-2018-25032, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2018-25032?

CVE-2018-25032 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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