USN-8639-1: libpng vulnerabilities

unknownCVE-2016-10087 CVE-2018-14048 CVE-2019-7317 CVE-2026-33416 CVE-2026-33636 CVE-2026-34757

Patrick Keshishian discovered that libpng incorrectly handled certain text chunks. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2016-10087) It was discovered that libpng incorrectly handled certain malformed images. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 18.04 LTS. (CVE-2018-14048) It was discovered that libpng incorrectly handled memory when freeing certain images. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 16.04 LTS. (CVE-2019-7317) It was discovered that libpng incorrectly handled memory when processing certain images. An attacker could possibly use this issue to cause a denial of service, or execute arbitrary code. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-33416) It was discovered that libpng incorrectly handled certain images. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-33636) It was discovered that libpng incorrectly handled memory when processing certain images. An attacker could possibly use this issue to cause a denial of service or obtain sensitive information. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-34757) Seung Min Shin discovered that libpng incorrectly handled certain animated images. An attacker could possibly use this issue to cause libpng to misinterpret image data. This issue only affected Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2026-40930)

CSIRTS triage

vendor: libpng product: libpng Denial of service Memory corruption Remote code execution

What: Multiple vulnerabilities in libpng involving incorrect handling of text chunks, malformed images, and memory management that can lead to denial of service or arbitrary code execution.
Who is affected: Ubuntu 14.04 LTS, 16.04 LTS, and 18.04 LTS systems with libpng are affected; specific libpng versions are not listed.
Urgency: Moderate to high urgency; memory corruption and RCE are possible, though exploitation status is unconfirmed.
Action: Apply the Ubuntu security update USN-8639-1 for libpng and verify affected systems are patched.

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

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Details

Source: Ubuntu Security Notices (INTL · vendor-psirt · site)
Severity: unknown
Published: 2026-08-17
Exploitation: Not in CISA KEV at last sync

Original advisory: https://ubuntu.com/security/notices/USN-8639-1

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.

Moderate exploitation riskCVE-2016-100875.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 92% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2018-140483.2% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 87% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2019-73179.4% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 95% of all EPSS-scored CVEs.
Moderate exploitation riskCVE-2026-334161.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 62% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-336360.74% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 52% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-347570.19% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 9% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-409300.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 10% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2016-10087	coverage & exploitation status	NVD · CVE.org
CVE-2018-14048	coverage & exploitation status	NVD · CVE.org
CVE-2019-7317	coverage & exploitation status	NVD · CVE.org
CVE-2026-33416	coverage & exploitation status	NVD · CVE.org
CVE-2026-33636	coverage & exploitation status	NVD · CVE.org
CVE-2026-34757	coverage & exploitation status	NVD · CVE.org
CVE-2026-40930	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

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

high[NEW] [high] IBM App Connect Enterprise: Multiple vulnerabilitiescert-bund
medium[UPDATE] [medium] libpng: Vulnerability enables denial of servicecert-bund
medium[UPDATE] [medium] libpng: Vulnerability Enables Information Disclosurecert-bund
medium[UPDATE] [medium] libpng: Multiple vulnerabilitiescert-bund
unknownSamsung Products Multiple Vulnerabilitieshkcert
mediumCVE-2026-40930: LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk bodymsrc