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.
CVE-2026-34757
MEDIUMNVD 5.15.1ElevatedEG-KEV Tier 3: ElevatedEG-KEV is EchelonGraph's own tiering of exploitation signals from CISA KEV, CISA's SSVC data (Vulnrichment), ransomware data, public exploit-code references and EPSS.Tier 3 is not evidence of exploitation. It means public exploit code is referenced, or CISA's SSVC data says "public PoC", or EPSS ranks the CVE in the top 5%.Signals for this CVE: CISA's SSVC exploitation value: public PoC.EchelonGraph confidence 38%: a heuristic from the tier and the number of signals, not a measured probability.
EchelonGraph scoreMEDIUM confidence
“—” beside the score: it is equal to NVD's CVSS score.
This medium-severity CVE scores 5.1 under NVD CVSS v3. EPSS exploit probability: 0.2% (5th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, NVD CVSS v3
5.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.1Exploit: No code on recordExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 5.1
- EG Score
- 5.1MEDIUMmedium confidence
- EG Risk
- 39EG Risk 39/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity51% × 45%Impact severity (EG Severity): CVSS 5.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation40% × 40%EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.2%
- EPSS %ILE
- 5th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.1): severity, escalated by confirmed exploitation. This CVE's 5.1 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.1 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
April 9, 2026
Last Modified
May 13, 2026
Advisory Details (6)
Auto-updated May 9, 2026Patch available. Sources: github.
Web pageMentions a patch (unverified)
[SECURITY] [DLA 4573-1] libpng1.6 security update
https://lists.debian.org/debian-lts-announce/2026/05/msg00017.htmlGitHub advisoryMentions a patch (unverified)
Use-after-free in `png_set_PLTE`, `png_set_tRNS` and `png_set_hIST` leading to corrupted chunk data and potential heap information disclosure · Advisory · pnggroup/libpng · GitHub
https://github.com/pnggroup/libpng/security/advisories/GHSA-6fr7-g8h7-v645Web page
Use-After-Free in `png_set_tRNS` Caused by Getter/Setter Pointer Aliasing · Issue #837 · pnggroup/libpng · GitHub
https://github.com/pnggroup/libpng/issues/837Web page
Use-after-free in png_set_PLTE, png_set_tRNS, and png_set_hIST when called with getter-returned pointers · Issue #836 · pnggroup/libpng · GitHub
https://github.com/pnggroup/libpng/issues/836Web page
fix: Handle getter-to-setter aliasing in append-style chunk setters · pnggroup/libpng@55d20aa · GitHub
https://github.com/pnggroup/libpng/commit/55d20aaa322c9274491cda82c5cd4f99b48c6bccWeb page
fix: Handle self-referencing pointers in getter-to-setter aliasing · pnggroup/libpng@398cbe3 · GitHub
https://github.com/pnggroup/libpng/commit/398cbe3df03f4e11bb031e07f416dfdde3684e8aVendor Advisories for CVE-2026-34757(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-34757Microsoft Security Response Center (MSRC)Medium
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
- RHSA-2026:13719Red Hat Product SecurityMedium
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
Patch Availability(2)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | libpng16-16t64 (1.6.50-1ubuntu0.5) @ questing | 2026-06-15 | ubuntu |
| redhat | libpng-main-1.6.57-0.1.hum1 | 2026-05-05 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(9 across 9 ecosystems)
Alpine:v3.20(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng | — |
| — |
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng1.6 | 1.6.37-3, 1.6.37-3+deb11u1, 1.6.37-3+deb11u2, 1.6.37-3+deb11u3 |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng1.6 | 1.6.39-2, 1.6.39-2+deb12u1, 1.6.39-2+deb12u2, 1.6.39-2+deb12u3, 1.6.39-2+deb12u4 |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng1.6 | 1.6.48-1, 1.6.48-1+deb13u1, 1.6.48-1+deb13u2, 1.6.48-1+deb13u3, 1.6.48-1+deb13u4 |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| libpng1.6 | 1.6.48-1 ... 1.6.56-1 (10 versions) |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(1)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 8× in last 7d / 29× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 97 of 200 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 3 repeat rows among the latest 100 are merged into the row they repeat. The 103 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-18 03:45 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
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- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.2% · 5th percentile
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- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-12 16:12 UTCEG score recompute
- 2026-10-11 19:54 UTCEG score recompute
- 2026-10-11 17:07 UTCEG score recompute
- 2026-10-11 14:34 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-10 21:33 UTCOSV refresh
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.2% · 5th percentile
- 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 5th percentile
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- 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 4th percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.2% · 4th percentile
- 2026-09-21 09:19 UTCOSV refresh
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-09-02 07:44 UTCOSV refresh
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-16 07:14 UTCEG score recompute
- 2026-08-16 07:14 UTCVendor advisory
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-14 05:09 UTCVendor advisory
- 2026-08-12 19:25 UTCEG score recompute
- 2026-08-12 19:25 UTCVendor advisory
- 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-11 05:13 UTCEG score recompute
- 2026-08-11 05:13 UTCVendor advisory
- 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-10 04:55 UTCEG score recompute
- 2026-08-10 04:55 UTCVendor advisory
- 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-09 04:36 UTCEG score recompute
- 2026-08-09 04:36 UTCVendor advisory
- 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-07 14:31 UTCEG score recompute
- 2026-08-07 14:31 UTCVendor advisory
- 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-05 23:47 UTCEG score recompute
- 2026-08-05 23:47 UTCVendor advisory
- 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-08-04 10:38 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-03 22:01 UTCEG score recompute
- 2026-08-03 22:01 UTCVendor advisory
- 2026-08-03 10:36 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-08-02 13:57 UTCEG score recompute
- 2026-08-02 13:57 UTCVendor advisory
- 2026-08-02 02:27 UTCEPSS rescoreEPSS 0.2% · 9th percentile
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- 2026-07-30 16:28 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-07-27 14:13 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-07-25 14:18 UTCEPSS rescoreEPSS 0.2% · 9th percentile
- 2026-07-24 14:17 UTCEPSS rescoreEPSS 0.2% · 9th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownAlpine:v3.20:libpng
Frequently asked(5)
What is CVE-2026-34757?
CVE-2026-34757 is a medium-severity vulnerability; its CVE record was published on April 9, 2026. 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 pnggetPLTE, pnggettRNS, or pnggethIST back into the corresponding setter on the same…
When was the CVE record for CVE-2026-34757 published?
The CVE record for CVE-2026-34757 was published on April 9, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of May 13, 2026; the record at its source may have been updated since.
Is CVE-2026-34757 actively exploited?
CVE-2026-34757 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (5th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-34757?
CVE-2026-34757 has a CVSS v3 base score of 5.1 (NVD).
How do I remediate CVE-2026-34757?
A fix for CVE-2026-34757 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-34757 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-34757
Is Your Infrastructure Affected by CVE-2026-34757?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.