[UPDATE] [medium] zlib: Vulnerability enables code execution
A remote anonymous attacker can exploit a vulnerability in zlib to execute arbitrary code or trigger a denial of service condition.
CSIRTS triage
- What
- A vulnerability in zlib enables arbitrary code execution or denial of service.
- Who is affected
- Systems and applications linked against vulnerable zlib versions.
- Urgency
- Medium: severity rated medium; code execution capability is serious but only affects older versions given CVE age.
- Action
- Apply zlib security updates and recompile or update dependent applications.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2022-0005
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Exploitation likely imminentCVE-2018-25032EPSS puts this in the most-targeted tier (51.7% 30-day exploitation probability). Prioritize alongside KEV items. Riskier than 99% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2018-25032 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- criticalexploitedSiemens CADRAcisa
- unknownNCSC-2026-0229 [1.00] [M/H] Vulnerabilities fixed in Siemens productsncsc-nl
- medium[UPDATE] [medium] Splunk Splunk Enterprise: Multiple vulnerabilities in third-party componentscert-bund
Recent advisories for zlib
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- lowCVE-2026-77640: tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip stre…nvd · 2026-08-20
- mediumCVE-2026-77639: Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate …nvd · 2026-08-20
- unknownCVE-2026-62292: libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.1, a crafte…nvd · 2026-08-18
- criticalCVE-2026-22184: zlib <= 1.3.1.2 untgz Global Buffer Overflow in TGZfname()msrc · 2026-08-06
- highCVE-2026-49158: Apache Thrift: Ruby THeaderTransport ZLIB Decompression Bombmsrc · 2026-08-06
- highCVE-2026-41608: Apache Thrift: Unbounded Zlib Decompression in Python THeaderTransportmsrc · 2026-08-06
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