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.
総合評価: CVE-2026-34757 は公開エクスプロイトあり（50/100）。CVSS 深刻度は中。悪用される可能性が高い（EPSS 0.19%、9 パーセンタイル） 根拠: 公開エクスプロイトが 2 件参照されています（Exploit-DB）。 推奨対応: 公開エクスプロイトが確認されています。影響範囲の確認、緩和策の適用、パッチ適用を優先してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
| EDB-ID | ソース | 種別 | 公開 | リンク |
|---|---|---|---|---|
| — | nvd_ref | exploit_tag | Exploit-DB ↗ | |
| — | nvd_ref | exploit_tag | Exploit-DB ↗ |
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.01% | 0.19% | +0.18% |
| 2 | 2026-04-10 | — | 0.01% | — |
EPSS の全履歴 （全 2 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 5.1 | 3.1 | MEDIUM |
|
2.5 | 2.5 | [email protected] |
| 4.4 | 3.1 | MEDIUM |
|
1.8 | 2.5 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2026-34757: 1 source package rows (libpng); 5 state rows across 5 repos (3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 5, open 0. | https://security.alpinelinux.org/vuln/CVE-2026-34757 |
debian
|
not yet assigned | CVE-2026-34757 not yet assigned priority: Debian including 1 source packages (libpng1.6), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2026-34757 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2026-34757 |
suse
|
medium | CVE-2026-34757 severity moderate: SUSE including 23 source package names (libpng15-15-1.5.22-10.10.1, libpng16-16-1.6.34-150000.3.25.1, …), 31 product×package rows across 10 product lines (SUSE Linux Enterprise Micro 5.2, SUSE Linux Enterprise Micro 5.3, … (10 product lines)): First Fixed 21, Fixed 10. | https://www.suse.com/security/cve/CVE-2026-34757/ |
ubuntu
|
medium | CVE-2026-34757 medium priority: Ubuntu including 5 source packages (chromium-browser, firefox, libpng, libpng1.6, thunderbird), 30 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): not-affected 13, needs-triage 8, released 5, DNE 4. | https://ubuntu.com/security/CVE-2026-34757 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| libpng | libpng | >= 1.0.9, < 1.6.57 | cpe:2.3:a:libpng:libpng:*:*:*:*:*:*:*:* |
| debian | debian_linux | 11.0 | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |
| URL | タグ |
|---|---|
| https://github.com/pnggroup/libpng/commit/398cbe3df03f4e11bb031e07f416dfdde3684e8a | Patch |
| https://github.com/pnggroup/libpng/commit/55d20aaa322c9274491cda82c5cd4f99b48c6bcc | Patch |
| https://github.com/pnggroup/libpng/issues/836 | Exploit Issue Tracking Mitigation |
| https://github.com/pnggroup/libpng/issues/837 | Exploit Issue Tracking Mitigation |
| https://github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v645 | Mitigation Patch Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2026/05/msg00017.html | Mailing List Third Party Advisory |