VulnSocial

CVE-2026-56403Disclosure(libexpat_project / libexpat)

LOWCVSS 6.9 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Patch libexpat_project libexpat systems immediately

Recommended action window: Monitor and triage in normal cycle

NVD description

libexpat before 2.8.2 has an integer overflow in storeAtts.

libexpat_project CVEsBack to dashboard
0.5/ 10 priority

Sources & remediation

Patch / fix
Weakness type (CWE)
CWE-190

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

If you run products in this scope, you should treat this CVE as relevant to your environment.

  • libexpat

Threat summary

  • Patch or workaround signal is available
  • 3 mentions across 2 observed days
  • Momentum state: stable

What's happening

  • Patch or workaround mentioned in 1 signal
  • Technical details provided in 3 signals
  • Disclosure: 2 classified signals
  • Peaked 1d ago at 2 mentions (2026-06-21); latest day: 1
  • 3 total mentions across 2 days

Affected systems

Vendors
libexpat_project
Products
libexpat

Deep dive

Activity timeline3 mentions / 2d
01122Mentions · 2026-06-21: 2Mentions · 2026-06-29: 1Patch / Workaround · 2026-06-29: 1Technical Details · 2026-06-21: 2Technical Details · 2026-06-29: 106-2106-29
Signal classification2 categories
Disclosure
266.7%
Patch
133.3%
Referenced assets3 URLs
Classification over time
DateTotalLabels
2026-06-212
Disclosure2
2026-06-291
Patch1
Full discourse3 posts
  • connect24h@connect24h
    Patch

    いやー、地味に嫌なんですけど。XMLを「通るだけの部品」と見ている組織ほど、libexpat 2.8.2未満は今日棚卸ししてほしい。CVE-2026-56403〜56407にinteger overflow、CVE-2026-56132にheap-based buffer overflow、CVE-2026-56131/56412にhandler call depth絡みのuse-after-free系が並ぶ。 単体アプリ名ではなく、OS・ミドルウェア・組込み製品・社内ツールに静かに入る波及性。SBOM、コンテナ、静的リンク、XMLを受ける入口を見て、2.8.2以上へ更新可否が必要。地味だけど、こういう基盤ライブラリは後回しが一番怖い。 #セキュリティ https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56405

    Post summary

    The post discloses several critical arithmetic and memory‑management flaws in libexpat 2.8.2‑minus versions and stresses the need to upgrade, without providing PoC or exploitation details.

    00001240
    4.1K followersView on X
  • Infoflowcloud@infoflowcloud
    Disclosure

    🚨*CVE* CVE-2026-56403 libexpat before 2.8.2 has an integer overflow in storeAtts. https://www.cve.org/CVERecord?id=CVE-2026-56403 ----- Traducción: CVE-2026-56403 libexpat anterior a 2.8.2 tiene un desbordamiento de entero en storeAtts. https://www.cve.org/CVERecord?id=CVE-2026-56403 Fuente: `CVEne… http://infoflow.cloud`

    Post summary

    The post announces CVE-2026-56403, detailing an integer overflow vulnerability in libexpat prior to 2.8.2, with no mention of PoC, exploit, or mitigation.

    0000037
    88 followersView on X
  • CVE@CVEnew
    Disclosure

    CVE-2026-56403 libexpat before 2.8.2 has an integer overflow in storeAtts. https://www.cve.org/CVERecord?id=CVE-2026-56403

    Post summary

    The text announces CVE‑2026‑56403, identifies it as an integer overflow in libexpat's storeAtts function affecting versions before 2.8.2, and links to the official CVE record.

    00000477
    57.7K followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Applibexpat_projectlibexpat---

Explore more

Back to dashboardlibexpat_project CVEslibexpat vulnerabilities