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Full vulnerability report · 2026
CVE-2026-50012High confidence

Squid: Memory corruption in cache_digest reply handling

squid-cache · squid

Official source article: GitHub GHSA-5VMX-9X64-9284 ↗. Check the applicable product and release in the original source.

5.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Medium, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • EPSS is 2.68% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs squid-cache squid and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

6 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainsquidVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.7.6-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcesquidVendor fix publishedDebian records a fixed source-package version for this release.6.13-2+deb13u2Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcesquidVendor fix publishedDebian records a fixed source-package version for this release.5.7-2+deb12u6Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcesquidVendor fix publishedDebian records a fixed source-package version for this release.7.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcesquidVendor fix publishedDebian records a fixed source-package version for this release.7.6-1Debian Security Tracker ↗Source updated 6 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivesquidVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.6.14-0ubuntu0.24.04.4Canonical Ubuntu Security ↗Source updated 5 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2026-50012 · CSAF 2.0 · revision 6 · interimSUSE Product Security TeamCVE-2026-50012
42 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • squid as component of SUSE Linux Enterprise High Performance Computing 12 SP4
  • squid as component of SUSE Linux Enterprise High Performance Computing 12 SP5
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP1
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP2
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP3
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP4
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
  • squid as component of SUSE Linux Enterprise High Performance Computing 15 SP5
  • squid as component of SUSE Linux Enterprise Module for Server Applications 15 SP7
  • squid as component of SUSE Linux Enterprise Server 12 SP4-LTSS
  • squid as component of SUSE Linux Enterprise Server 12 SP4
Summary
Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.
Remediation
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-44961

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.

What

Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Squid is a caching proxy for the Web. Prior to 7.6, due to an improper input validation bug in cache digest reply handling (peerDigestSwapInMask in src/peer_digest.cc), Squid is vulnerable to a heap-based buffer overflow: a cache digest's on-the-wire size may be larger than the mask_size declared within the digest, so a trusted peer sending a maliciously crafted reply to a cache_digest request message can trigger the overflow. This attack is limited to Squid instances compiled with the --enable-cache-digests option and configured with cache_peer entries. This issue is fixed in version 7.6.

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Input Validation → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
High: elevated access is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-20 ↗

CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.ILowIntegrity impact: A successful attack can cause a limited loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-20
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2026-1920Squid: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Squid ausnutzen, um Informationen offenzulegen und um einen nicht näher spezifizierten Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260722Security Bulletin 22 Jul 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 22 Jul 2026, published on 22 July 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2026-AVI-0795Multiples vulnérabilités dans Squid

De multiples vulnérabilités ont été découvertes dans Squid. Elles permettent à un attaquant de provoquer une atteinte à la confidentialité des données et un problème de sécurité non spécifié par l'éditeur.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-024611Squid-cache.orgのSquidにおける複数の脆弱性

Squidはウェブ向けのキャッシュプロキシです。バージョン7.6以前では、cache digestの応答処理（src/peer_digest.ccのpeerDigestSwapInMask）における不適切な入力検証のバグにより、Squidにヒープベースのバッファオーバーフローの脆弱性が存在します。キャッシュダイジェストのオンザワイヤサイズが、ダイジェスト内で宣言されたmask_sizeより大きくなる可能性があり、そのため信頼されたピアが悪意を持って細工したcache_digestリクエストメッセージへの応答を送信すると、オーバーフローが発生する可能性があります。この攻撃は、--enable-cache-digestsオプション付きでコンパイルされ、かつcache_peer設定があるSquidインスタンスに限定されます。この問題はバージョン7.6で修正されています。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
7.6.
Action
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 16 Jul 2026 · Last source change 17 Jul 2026, 14:04 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-44961
Product sourceVendor CSAF · SUSE Product Security Team
Remediation sourceVendor CSAF · SUSE Product Security Team
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Vendor guidanceAuthoritative vendor guidance changed from remediation: suse.com/CVE-2026-50012 to remediation: suse.com/CVE-2026-50012.
    Before
    remediation: suse.com/CVE-2026-50012
    After
    remediation: suse.com/CVE-2026-50012
    SUSE Product Security Team ↗
  2. Remediation statusRemediation status changed from Awaiting fix to Patch available.
    Before
    Awaiting fix
    After
    Patch available
    SUSE Product Security Team ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-44961↗Vendor CSAF · SUSE Product Security Team↗CVE authority or vendor reference · GitHub GHSA-5VMX-9X64-9284↗Patch or update reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-50012 · cve.blacktree.nl