[UPDATE] [medium] gzip: Multiple vulnerabilities

mediumCVE-2026-41991 CVE-2026-41992

A local attacker can exploit multiple vulnerabilities in gzip to manipulate files and disclose confidential information.

CSIRTS triage

vendor: gzip product: gzipOther

What: Multiple vulnerabilities allow a local attacker to manipulate files and disclose confidential information.
Who is affected: Local attackers exploiting vulnerabilities in gzip.
Urgency: Remediation is medium urgency due to the potential for information disclosure.
Action: Update to the latest version of gzip.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-08-17
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2126

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.

Low exploitation riskCVE-2026-419910.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-419920.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 27% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-41991	coverage & exploitation status	NVD · CVE.org
CVE-2026-41992	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for gzip

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.

highGHSA-6ccx-9c9f-327w: gRPC Erlang package has unbounded gzip decompression (decompression bomb)ghsa · 2026-08-25
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
highCVE-2026-75936: Improper handling of highly compressed data in the GZIP auto-decompression handler in Amazon i…nvd · 2026-08-18
highGHSA-g4w2-6h2r-3m3w: http4k: Unbounded gzip decompression in `ServerFilters.GZip` / `RequestFilters.GunZip` al…ghsa · 2026-08-17
highCVE-2026-68981: Apache NiFi 1.5.0 through 2.10.0 support gzip-encoded HTTP requests for the application REST A…nvd · 2026-08-03
unknownCVE-2026-66913: Lookyloo did not enforce limits on the decompressed size of uploaded capture archives and comp…nvd · 2026-07-28