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Full vulnerability report · 2026
CVE-2026-34757High confidence

LIBPNG has a yse-after-free in png_set_PLTE, png_set_tRNS and png_set_hIST leading to corrupted chunk data and potential heap information disclosure

pnggroup · libpng

Official source article: GitHub GHSA-6FR7-G8H7-V645 ↗. Check the applicable product and release in the original source.

5.1MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • EPSS is 0.16% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs pnggroup libpng and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

8 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainlibpngVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.6.57-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainlibpngVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.6.57-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainlibpngVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.1.6.57-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcelibpng1.6Vendor fix publishedDebian records a fixed source-package version for this release.1.6.48-1+deb13u5Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcelibpng1.6Vendor fix publishedDebian records a fixed source-package version for this release.1.6.39-2+deb12u5Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcelibpng1.6Vendor fix publishedDebian records a fixed source-package version for this release.1.6.57-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcelibpng1.6Vendor fix publishedDebian records a fixed source-package version for this release.1.6.57-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivelibpng1.6Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.1.6.43-5ubuntu0.6Canonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-34757 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitylibpng: libpng: Information disclosure and data corruption via use-after-free vulnerability
282 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • java-1.8.0-openjdk-portable.src as a component of Red Hat build of OpenJDK 1.8
  • java-17-openjdk.src as a component of Red Hat build of OpenJDK 1.8
  • java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 1.8
  • java-21-openjdk.src as a component of Red Hat build of OpenJDK 1.8
  • java-11-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-11-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-17-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-21-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS
  • java-17-openjdk-portable.src as a component of Red Hat build of OpenJDK 17
  • java-17-openjdk.src as a component of Red Hat build of OpenJDK 17
Summary
A flaw was found in libpng, a library used for handling PNG (Portable Network Graphics) image files. This vulnerability arises when an application reuses a pointer, previously obtained from functions like png_get_PLTE, by passing it back to a corresponding setter function within the same image structure. This action causes the setter to access memory that has already been deallocated, leading to a use-after-free condition. A local attacker could potentially exploit this flaw to corrupt image metadata or disclose sensitive information from the application's memory.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-20897

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

What

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaking unrelated heap contents into the chunk struct). This vulnerability is fixed in 1.6.57.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
local access → Use After Free → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-416 ↗

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CLowConfidentiality impact: A successful attack can cause a limited loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedCWE-416Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-1023libpng: Schwachstelle ermöglicht Offenlegung von Informationen

Ein lokaler Angreifer kann eine Schwachstelle in libpng ausnutzen, um Informationen offenzulegen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260415Security Bulletin 15 April 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 15 April 2026, published on 15 April 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0445Multiples vulnérabilités dans les produits Microsoft

De multiples vulnérabilités ont été découvertes dans les produits Microsoft. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un déni de service à distance. Microsoft indique que la vulnérabilité CVE-2026-32201 est activement exploitée.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-015684Debian等の複数ベンダの製品における解放済みメモリの使用に関する脆弱性

LIBPNGは、PNG（Portable Network Graphics）ラスター画像ファイルを読み取り、作成し、操作するアプリケーションで使用されるリファレンスライブラリです。バージョン1.0.9から1.6.57未満の間において、png_get_PLTE、png_get_tRNS、またはpng_get_hISTから取得したポインタを同じpng_struct/png_infoペアの対応するセッターに渡すと、セッターは解放されたメモリから読み取り、その内容を置換バッファにコピーしてしまいます。セッターは呼び出し元が提供したポインタからコピーする前に内部バッファを解放するため、ポインタはダングリング状態になります。解放済みの領域には古いデータ（サイレントに破損したチャンクメタデータを生成する可能性があります）や後続のヒープ割り当てからのデータ（チャンク構造体に関係のないヒープ内容が漏洩する可能性があります）が含まれることがあります。この脆弱性はバージョン1.6.57で修正されました。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 9 Apr 2026 · Last source change 9 May 2026, 10:21 UTC · CWE-416 · Use After Free

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-20897
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    >= 1.0.9, < 1.6.57 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    >= 1.0.9, < 1.6.57 · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
    Red Hat Product Security ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    java-1.8.0-openjdk-portable.src as a component of Red Hat build of OpenJDK 1.8; java-17-openjdk.src as a component of Red Hat build of OpenJDK 1.8; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 1.8; java-21-openjdk.src as a component of Red Hat build of OpenJDK 1.8; java-11-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS; java-11-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-17-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 11 ELS; java-21-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS; java-17-openjdk-portable.src as a component of Red Hat build of OpenJDK 17; java-17-openjdk.src as a component of Red Hat build of OpenJDK 17; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 17; java-21-openjdk.src as a component of Red Hat build of OpenJDK 17; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 17; java-17-openjdk.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk-portable.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk.src as a component of Red Hat build of OpenJDK 21; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 21; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 25; firefox as a component of Red Hat Enterprise Linux 10; firefox.src as a component of Red Hat Enterprise Linux 10; java-21-openjdk as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo-fastdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo-slowdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel-fastdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel-slowdebug as a component of Red Hat Enterprise Linux 10; and 251 more · Fixed: libpng-main@aarch64 as a component of Red Hat Hardened Images; libpng-main@src as a component of Red Hat Hardened Images; libpng-main@x86_64 as a component of Red Hat Hardened Images
    After
    java-1.8.0-openjdk-portable.src as a component of Red Hat build of OpenJDK 1.8; java-17-openjdk.src as a component of Red Hat build of OpenJDK 1.8; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 1.8; java-21-openjdk.src as a component of Red Hat build of OpenJDK 1.8; java-11-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS; java-11-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-17-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 11 ELS; java-21-openjdk.src as a component of Red Hat build of OpenJDK 11 ELS; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 11 ELS; java-17-openjdk-portable.src as a component of Red Hat build of OpenJDK 17; java-17-openjdk.src as a component of Red Hat build of OpenJDK 17; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 17; java-21-openjdk.src as a component of Red Hat build of OpenJDK 17; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 17; java-17-openjdk.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk-portable.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk-vanilla.src as a component of Red Hat build of OpenJDK 21; java-21-openjdk.src as a component of Red Hat build of OpenJDK 21; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 21; java-25-openjdk-portable.src as a component of Red Hat build of OpenJDK 25; firefox as a component of Red Hat Enterprise Linux 10; firefox.src as a component of Red Hat Enterprise Linux 10; java-21-openjdk as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo-fastdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-demo-slowdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel-fastdebug as a component of Red Hat Enterprise Linux 10; java-21-openjdk-devel-slowdebug as a component of Red Hat Enterprise Linux 10; and 252 more · Fixed: libpng-main@aarch64 as a component of Red Hat Hardened Images; libpng-main@src as a component of Red Hat Hardened Images; libpng-main@x86_64 as a component of Red Hat Hardened Images
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2026-20897↗Red Hat Product Security security advisory↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference · GitHub GHSA-6FR7-G8H7-V645↗Public exploit reference↗Public exploit reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-34757 · cve.blacktree.nl