VulnSocial

CVE-2026-58050PoC(libssh2 / libssh2)

HIGHCVSS 7.5 · HIGH

Exploitation observed; activity peaked at 7 mentions and remains active

Immediate actions

  • Patch libssh2 libssh2 systems immediately
  • Assume compromise if assets are exposed
  • Hunt for exploitation attempts and persistence artifacts
  • Increase monitoring for publicly documented tradecraft

Recommended action window: Immediate (within 24h)

NVD description

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

libssh2 CVEsBack to dashboard
7.5/ 10 priority

Sources & remediation

Vendor / third-party advisories
Other references
Weakness type (CWE)
CWE-190

Priority

HIGH

Exploitation

ACTIVE

PoC

YES

Patch

AVAILABLE

Momentum

STABLE

Are you affected?

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

  • libssh2

Threat summary

  • Active exploitation appears in 1 classified signals
  • Public PoC and exploit tooling are both present
  • Patch or workaround signal is available
  • 11 mentions across 3 observed days

What's happening

  • Active exploitation reported across 1 signal
  • Exploit tool or code specified in 2 signals
  • PoC mentioned or linked in 7 signals
  • Patch or workaround mentioned in 5 signals
  • Technical details provided in 8 signals
  • Disclosure: 1 classified signal
  • Peaked 2d ago at 7 mentions (2026-06-28); latest day: 1
  • 11 total mentions across 3 days

Affected systems

Vendors
libssh2
Products
libssh2

Deep dive

Activity timeline11 mentions / 3d
02457Mentions · 2026-06-28: 7Mentions · 2026-06-29: 3Mentions · 2026-07-01: 1PoC Mentioned / Linked · 2026-06-28: 4PoC Mentioned / Linked · 2026-06-29: 2PoC Mentioned / Linked · 2026-07-01: 1Exploit Tool / Code · 2026-06-28: 1Exploit Tool / Code · 2026-06-29: 1Active Exploitation · 2026-06-29: 1Patch / Workaround · 2026-06-28: 4Patch / Workaround · 2026-07-01: 1Technical Details · 2026-06-28: 7Technical Details · 2026-07-01: 106-2806-2907-01
Signal classification4 categories
PoC
763.6%
Patch
218.2%
Disclosure
19.1%
Active Exploitation
19.1%
Referenced assets6 URLs
Classification over time
DateTotalLabels
2026-06-287
Disclosure1Patch2PoC4
2026-06-293
Active Exploitation1PoC2
2026-07-011
PoC1
Full discourse11 posts
  • yousukezan@yousukezan
    PoC

    libssh2に、悪意あるSSHサーバーへ接続したクライアント側のヒープを破壊できる脆弱性が公開された。CVE-2026-58050として追跡され、概念実証コードもすでに公開されている。 この脆弱性はlibssh2のpublickeyサブシステムの解析処理に存在する。サーバー応答から32ビットの属性数を読み取り、その数に構造体サイズを掛けてバッファを確保するが、32ビット環境では整数オーバーフローにより小さな領域が確保される。その後の処理でバッファ外へ書き込み、ヒープ破壊につながる。 libssh2はファイル転送クライアント、自動化ツール、言語バインディング、組み込み機器などでSSH機能に利用されるため、影響は単一製品にとどまらない。攻撃対象はサーバーではなく接続するクライアントであり、利用者が悪意あるSSHサーバーや乗っ取られたサーバーへ接続した場合にリスクが生じる。サーバーになりすます中間者攻撃者も同様の条件を満たす。 影響を受けるのはlibssh2 1.11.1以前の全バージョンで、主な懸念は32ビット環境での乗算の回り込みである。修正では属性数の境界チェックを追加し、新しいリスト要素をゼロ初期化する。現時点で実際の悪用は確認されていないが、公開PoCが存在するため、利用者は修正版への更新と、同梱ライブラリを含むアプリやコンテナの再ビルドが求められる。 https://securityonline.info/libssh2-vulnerability-cve-2026-58050/

    Post summary

    A client‑side heap‑corruption flaw in libssh2 (CVE‑2026‑58050) has been disclosed with a published proof of concept; a patch is available and users are advised to update, but no active exploitation has been observed.

    010235143.8K
    14.8K followersView on X
  • Daily CyberSecurity@the_yellow_fall
    PoC

    Researchers publicly disclosed a libssh2 vulnerability, CVE-2026-58050, with PoC code. A malicious SSH server can corrupt a client's heap. Patch now. #libssh2 #CVE202658050 #SSH #HeapOverflow #PoC #Cybersecurity #Infosec https://securityonline.info/libssh2-vulnerability-cve-2026-58050 https://t.co/4USrAbk3ln

    Post summary

    CVE-2026-58050, a libssh2 heap overflow, has been publicly disclosed with proof‑of‑concept code available, and a patch has already been released to mitigate the vulnerability.

    0902642.3K
    12.8K followersView on X
  • GovCERT.CZ@GOVCERT_CZ
    PoC

    🚨 Upozorňujeme na RCE zranitelnost v libssh2, CVE-2026-58050. Zranitelnost typu přetečení haldy způsobená přetečením celého čísla se nachází v publickey subsystému (attribute parser) knihovny libssh2 a ovlivňuje všechny verze do 1.11.1 včetně. K chybě dochází v důsledku nedostatečné validace 32bitové hodnoty počtu atributů dodané serverem, což může při alokaci paměti na 32bitových systémech vést k přetečení integeru a následné korupci paměti na haldě. Zneužití je možné vzdáleně prostřednictvím škodlivého nebo kompromitovaného SSH serveru, případně serveru pod kontrolou útočníka typu Man-in-the-Middle, který zašle speciálně upravenou odpověď. Zranitelnost umožňuje vzdálené spuštění kódu, přičemž byl zveřejněn veřejně dostupný proof-of-concept exploit zvyšující pravděpodobnost budoucího zneužití. 📌Doporučujeme aktualizovat na nejnovější verzi.

    Post summary

    The tweet announces CVE-2026-58050, a heap overflow RCE in libssh2, notes a publicly available proof‑of‑concept exploit, and advises users to upgrade the library.

    1201671.6K
    4.3K followersView on X
  • kokumօtօ@__kokumoto
    PoC

    libssh2の脆弱性CVE-2026-58050に対応するPoC（攻撃の概念実証コード）が公表された。CVSSv4スコア8.3のヒープ破壊。公開鍵サブシステムのパーサがサーバから32ビットの属性カウントを読み込む際に32ビットシステムで構造体が溢れるもの。 https://securityonline.info/libssh2-vulnerability-cve-2026-58050/

    Post summary

    A PoC for CVE‑2026‑58050 has been released, detailing a heap‑based overflow with a CVSSv4 score of 8.3; no patch, active exploitation, or debunking information is present.

    0101031.3K
    7.7K followersView on X
  • Vulmon Vulnerability Feed@VulmonFeeds
    Disclosure

    CVE-2026-58050 Heap Buffer Overflow in libssh2 Through 1.11.1 via Integer Overflow https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-58050

    Post summary

    The post simply discloses CVE‑2026‑58050, a heap buffer overflow resulting from an integer overflow in libssh2 through version 1.11.1, with no further details on PoC, exploit, or mitigation.

    00021157
    4.1K followersView on X
  • VulDB 🛡@vuldb
    Active Exploitation

    It is possible to see elevated activities targeting libssh2 (CVE-2026-58050) https://vuldb.com/vuln/374507/cti

    Post summary

    The post notes increased activity against libssh2 related to CVE-2026-58050, implying potential active exploitation, but provides no PoC, technical details, or mitigation information.

    00010120
    2.2K followersView on X
  • techs_targe@techs44576
    PoC

    libssh2（1.11.1以前）に深刻な脆弱性 libssh2を利用しているソフトはアップデートを確認したほうがよい。特に32bit環境では細工されたSSHサーバーへの接続でヒープバッファオーバーフローが発生する可能性がある。CVE-2026-58050。PoC公開済み。 https://www.vulncheck.com/advisories/libssh2-integer-overflow-in-publickey-subsystem-attribute-allocation

    Post summary

    A PoC for CVE-2026‑58050 is publicly available, indicating a heap buffer overflow in libssh2, but there are no reports of active exploitation or published patches.

    00010126
    473 followersView on X
  • Upwind Security MDR@UpwindMDR
    Patch

    🚨High - libssh2 Multiple Memory Corruption Issues (CVE-2026-58050 & CVE-2026-58051) Two related vulnerabilities in libssh2 through 1.11.1: CVE-2026-58050: Integer overflow in publickey subsystem attribute allocation on 32-bit platforms allows heap buffer overflow. CVE-2026-58051: Uninitialized pointer free in publickey list cleanup after parse failure. A malicious SSH server can trigger both with malformed publickey responses, leading to memory corruption, denial of service, or potentially arbitrary code execution in the client. 👉Affected: libssh2 <= 1.11.1 Action: Upgrade to the latest patched version.

    Post summary

    Two memory‑corruption vulnerabilities (CVE‑2026‑58050 and CVE‑2026‑58051) were disclosed for libssh2 up to version 1.11.1, and users are advised to upgrade to the latest patched release.

    00010108
    232 followersView on X
  • moton@moton
    PoC

    libssh2 Vulnerability CVE-2026-58050 PoC Code Released - https://securityonline.info/libssh2-vulnerability-cve-2026-58050/

    Post summary

    A PoC code for CVE-2026-58050 in libssh2 has been released and linked. No information about active exploitation, patches, or technical details is provided.

    0000076
    659 followersView on X
  • キタきつね@foxbook
    PoC

    libssh2の脆弱性CVE-2026-58050に対する概念実証（PoC）エクスプロイトが公開される libssh2 Vulnerability CVE-2026-58050 Gets Public PoC Exploit #DailyCyberSecurity (Jun 28) https://securityonline.info/libssh2-vulnerability-cve-2026-58050/

    Post summary

    A public proof‑of‑concept exploit for CVE‑2026‑58050 in libssh2 has been announced, but no detailed technical information, attack reports, or patch notes are provided.

    00000295
    4.9K followersView on X
  • ADK Cyber@ADKCyber
    Patch

    CVE-2026-58050 (CVSS 8.3) impacts libssh2 &lt;=1.11.1 via unchecked allocation in publickey responses. Review and patch if your environment uses it: https://nvd.nist.gov/vuln/detail/CVE-2026-58050 via NVD Recent High CVSS #CyberSecurity #InfoSec #Vulnerability #AI #MachineLearning https://t.co/oLGWg10hwS

    Post summary

    The tweet highlights a CVSS‑8.3 flaw in libssh2 (<=1.11.1) with an unchecked allocation and urges users to review and apply the available patch via the NVD link.

    0000040
    92 followersView on X
CPE platform detail1 entries

1 of 1 entries

PartVendorProductVersionTarget SWTarget HW
Applibssh2libssh2---

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