Security readout for executives and security teams
Plain-English summary
MuPDF can crash when handling crafted barcode-decoding input because the same image buffer may be freed twice after a rendering error. Business impact is mainly denial of service for applications or services that process untrusted documents with MuPDF barcode decoding enabled.
Executive priority
Treat as a moderate availability risk. Prioritize internet-facing or automated document-processing services first, especially where crashes interrupt customer workflows or batch processing. No source provided evidence of active exploitation.
Technical view
CVE-2026-25556 is a CWE-415 double free in fz_fill_pixmap_from_display_list(). Its exception path drops a caller-owned fz_pixmap, then callers such as fz_decode_barcode_from_display_list can drop it again during cleanup. Sources describe affected MuPDF versions 1.23.0 through 1.27.0.
Likely exposure
Exposure is likely limited to products or services embedding MuPDF 1.23.0 through 1.27.0 and enabling barcode decoding on untrusted content. Confirm downstream package versions because the source bundle's affected-version detail is not fully consistent.
Exploitation context
The source bundle describes crafted input causing a rendering-time error during barcode decoding. CVSS requires user interaction and attack prerequisites. The CVE is not marked in KEV, and the provided sources do not state active exploitation.
Researcher notes
Focus triage on ownership semantics around fz_pixmap during exception handling. The patch reference is available, but this analysis does not infer memory-corruption impact beyond heap corruption and process crash described in sources.
Mitigation direction
- Apply the referenced MuPDF vendor patch or update per Artifex guidance.
- Inventory applications and third-party products that embed MuPDF.
- Prioritize systems that process untrusted documents or images.
- If patching is delayed, check vendor guidance for supported temporary mitigations.
- Consider disabling barcode decoding for untrusted inputs where operationally acceptable.
Validation and detection
- Confirm deployed MuPDF versions in applications and bundled dependencies.
- Verify whether barcode decoding is enabled or reachable from user-supplied content.
- Check whether the referenced patch is present in your MuPDF build.
- Review crash logs for MuPDF rendering failures during barcode decoding.
- Confirm vendors of embedded products have shipped patched builds.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-415: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-25556 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.9 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
5.9MediumVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://bugs.ghostscript.com/show_bug.cgi?id=709029CVE reference, VulnCheck · issue-tracking
- https://cgit.ghostscript.com/cgi-bin/cgit.cgi/mupdf.git/commit/?id=d4743b6092d513321c23c6f7fe5cff87cde043c1CVE reference, VulnCheck · patch
- https://mupdf.com/CVE reference, VulnCheck · product
- https://www.vulncheck.com/advisories/mupdf-barcode-decoding-double-freeCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Double Free
Double Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.