PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the request. Some contexts may not properly account for this scenario and leave request memory in an uninitialized state before performing an allocation. The subsequent request cleanup procedure may read or branch on this memory. Multiple OOM strategies can consistently trigger this condition and lead to remote code execution (RCE).
CVE-2026-109618
CRITICALNVD 9.89.8Trending — 4 sources updated this weekElevatedEG-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: other public exploit code (a GitHub or vendor proof of concept, or an Exploit-DB entry not marked verified).First public exploit code on record: 2026-10-21 (GitHub PoC 0x4148/CVE-2026-109618-php2shell-lab, and 9 more references that day)EchelonGraph confidence 38%: a heuristic from the tier and the number of signals, not a measured probability.
EchelonGraph scoreLOW confidence
This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). No GitHub Security Advisory CVSS is on record for this CVE.
Triggered by: Headline CVSS from NVD CVSS v3
Sources: NVD CVSS v3
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
- Public exploit or proof-of-concept code is available
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.8Exploit: Public PoCExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 9.8
- EG Score
- 9.8CRITICALlow confidence
- EG Risk
- 60EG Risk 60/100
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)Severity98% × 45%Impact severity (EG Severity): CVSS 9.8 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 none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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
- —
- EPSS %ILE
- —
- 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 (9.8): severity, escalated by confirmed exploitation. This CVE's 9.8 is its impact severity (EG Severity), not escalated.
- EG Severity
- 9.8 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
- EG Likelihood
- Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
- 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: 14 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 none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 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 total (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
October 21, 2026
Last Modified
October 22, 2026
Advisory Details (1)
Auto-updated Oct 21, 2026Patch available. Sources: github.
GitHub advisoryMentions a patch (unverified)
RCE via OOM corruption · Advisory · php/php-src · GitHub
https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79wVendor Advisories for CVE-2026-109618(10)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- 2026-143-AWSAWS Security BulletinsHigh
PHP web runtimes (CVE-2026-109618 and CVE-2026-109619)
- RHSA-2026:87079Red Hat Product SecurityHigh
Red Hat Security Advisory: php:8.3 security update
- RHSA-2026:87072Red Hat Product SecurityHigh
Red Hat Security Advisory: php:8.2 security update
- RHSA-2026:87073Red Hat Product SecurityHigh
Red Hat Security Advisory: php:8.2 security update
- RHSA-2026:87070Red Hat Product SecurityHigh
Red Hat Security Advisory: php security update
- RHSA-2026:87071Red Hat Product SecurityHigh
Red Hat Security Advisory: php8.4 security update
- RHSA-2026:87151Red Hat Product SecurityHigh
Red Hat Security Advisory: php security update
- CVE-2026-109618Palo Alto Networks Security AdvisoriesHigh
CVE-2026-109618 Impact of Critical Vulnerabilities in PHP (CVE-2026-109618, CVE-2026-109619) on Palo Alto Networks Products
- +2 more
Patch Availability(2)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | php8.5-zip (8.5.9-0ubuntu2.1) @ stonking | 2026-10-21 | ubuntu |
| ubuntu | php7.0-zip (7.0.33-0ubuntu0.16.04.16+esm22) @ xenial | 2026-10-21 | ubuntu |
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.
Weakness Classification(5)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
All Vendor Advisories
(2)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 14× in last 7d / 14× 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.
- 2026-10-21 17:26 UTCVendor advisory
- 2026-10-21 17:05 UTCEG score recompute▲ 0.60
- 2026-10-21 17:05 UTCVendor advisory
- 2026-10-21 17:05 UTCNVD updateCVSS v3 → 9.8
- 2026-10-21 16:25 UTCEG score recompute
- 2026-10-21 16:25 UTCVendor advisory
- 2026-10-21 15:25 UTCEG score recompute
- 2026-10-21 15:25 UTCVendor advisory
- 2026-10-21 14:51 UTCEG score recompute
- 2026-10-21 14:51 UTCVendor advisory
- 2026-10-21 14:28 UTCEG score recompute
- 2026-10-21 14:28 UTCVendor advisory
- 2026-10-21 13:56 UTCEG score recomputeFirst assessed: 9.2 CRITICAL
- 2026-10-21 13:55 UTCMITRE cvelistV5first tracked
Publicly available exploits
(10 references)Public exploit code is referenced for this CVE (10 GitHub PoCs). Defenders should treat patch urgency accordingly.
- GitHub PoC0x4148/CVE-2026-109618-php2shell-labPublished Oct 21, 2026
PHP2Shell (CVE-2026-109618 / CVE-2026-109619) Docker lab and PoC. Use-After-Free in PHP's session.upload_progress.
Open source ↗ - Open source ↗GitHub PoC19h/CVE-2026-109618Published Oct 21, 2026
- GitHub PoCeness/php2shell-CVE-2026-109618-CVE-2026-109619-PoCPublished Oct 21, 2026
Proof-of-Concept (PoC) exploit for php2shell (CVE-2026-109618 / CVE-2026-109619), demonstrating remote code execution in vulnerable PHP environments. For security research and educational purposes only.
Open source ↗ - GitHub PoCHOSTED-POWER/php_uploadprogress_guardPublished Oct 21, 2026
Stopgap for php2shell (CVE-2026-109618 / CVE-2026-109619): tiny PHP extension that detaches the session upload-progress handler at startup. PHP 5.6-8.5, Debian/Sury, cPanel, DirectAdmin.
Open source ↗ - GitHub PoCikow/php2shell-pocPublished Oct 21, 2026
CVE-2026-109618/109619 PHP session.upload_progress Exploit Research — POC & Analysis
Open source ↗ - Open source ↗GitHub PoCjunaire/CVE-2026-109618-exploitPublished Oct 21, 2026
- GitHub PoCmikensec/php2shell-labPublished Oct 21, 2026
Offline, reproducible lab to safely analyse an untrusted PoC for CVE-2026-109618/109619 and build detection rules. No exploit included; bring your own sample.
Open source ↗ - Open source ↗GitHub PoCrichardmongler/php2shell-CVE-2026-109618Published Oct 21, 2026
- GitHub PoCsyhunt/php2shell-protectionPublished Oct 21, 2026
Emergency Apache mitigation and testing toolkit for the zero day php2shell (CVE-2026-109618 / CVE-2026-109619), blocking multipart POST requests before they reach PHP.
Open source ↗ - GitHub PoCZer061/CVE-2026-109618Published Oct 21, 2026
PoC CVE-2026-109618 / -109619 (PHP session.upload_progress heap UAF)
Open source ↗
Related CVEs(same vendor + same CWE)
Frequently asked(4)
What is CVE-2026-109618?
CVE-2026-109618 is a critical-severity vulnerability; its CVE record was published on October 21, 2026. PHP uses longjmp() for out-of-memory (OOM) errors to exit the current context and abort handling of the request. Some contexts may not properly account for this scenario and leave request memory in an uninitialized state before performing an allocation. The subsequent request cleanup procedure may…
When was the CVE record for CVE-2026-109618 published?
The CVE record for CVE-2026-109618 was published on October 21, 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 October 22, 2026; the record at its source may have been updated since.
What is the CVSS score of CVE-2026-109618?
CVE-2026-109618 has a CVSS v3 base score of 9.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-109618?
A fix for CVE-2026-109618 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-109618 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-109618
Is Your Infrastructure Affected by CVE-2026-109618?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.