CVE-2026-55891

UNRATEDCVSS · not yet scoredElevated
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EchelonGraph verdictPlan a fixWithin your standard update timelines — no confirmed exploitation yet.
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS v2: —Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, Request::getRequestUri() in lib/Request.php passes $_SERVER['REQUEST_URI'] through FILTER_SANITIZE_URL, which does not remove quotation marks, angle brackets, or apostrophes, and Controller::_init() stores the attacker-controlled value in Controller::$_urlBase. Controller::_jsonld() in lib/Controller.php then uses str_replace() to insert that value without JSON escaping into js/types.jsonld, js/paste.jsonld, and the other JSON-LD templates used by /?jsonld= and /?pasteid. A raw quotation mark delivered by an HTTP client, proxy, or structured-data crawler that does not normalize the request target can break out of the JSON string and inject arbitrary key-value data into a CORS-open application/ld+json response. The jsonld branch in Controller::__construct() returns before _setCacheHeaders(), so the response also lacks X-Content-Type-Options: nosniff, Content Security Policy, X-Frame-Options, and Referrer-Policy. Direct script execution was not demonstrated, but manipulated responses can affect structured-data consumers or combine with less strict clients. This issue is fixed in version 2.0.5.

CVSS v3
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EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
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EPSS PROB
0.5%
EPSS %ILE
43rd
KEV
Not listed

BOD 26-04 (CISA's remediation timeline, Table 1)60 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 partial (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

August 28, 2026

Last Modified

September 9, 2026

References (3)

Vendor Advisories for CVE-2026-55891(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFix by version rangeDependents
privatebin/privatebin1.0 ... 2.0.4 (35 versions)
  • every version up to 2.0.5: fixed in 2.0.5
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Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 31× 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.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  3. 2026-10-12 15:55 UTCEG score recompute
  4. 2026-10-11 19:38 UTCEG score recompute
  5. 2026-10-11 16:53 UTCEG score recompute
  6. 2026-10-11 14:16 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  15. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  16. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  18. 2026-10-01 01:21 UTCEG score recompute
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  20. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  22. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  23. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  24. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.3% · 26th percentile
Show 23 more
  1. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  2. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 26th percentile
  3. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  4. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  5. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  6. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  7. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  8. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  9. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  10. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  11. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  12. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  13. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  14. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  15. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  16. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  17. 2026-08-31 19:20 UTCNVD update
  18. 2026-08-31 18:56 UTCEG score recompute
  19. 2026-08-31 18:49 UTCMITRE cvelistV5
  20. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  21. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  22. 2026-08-28 22:34 UTCNVD update
  23. 2026-08-28 21:11 UTCEG score recompute

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Frequently asked(4)

What is CVE-2026-55891?
CVE-2026-55891 is a vulnerability whose severity is not yet rated; its CVE record was published on August 28, 2026. PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, Request::getRequestUri() in lib/Request.php passes $SERVER['REQUESTURI'] through FILTERSANITIZEURL, which does not remove quotation marks, angle brackets, or apostrophes, and Controller::init()…
When was the CVE record for CVE-2026-55891 published?
The CVE record for CVE-2026-55891 was published on August 28, 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 September 9, 2026; the record at its source may have been updated since.
Is CVE-2026-55891 actively exploited?
CVE-2026-55891 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-55891?
A fix for CVE-2026-55891 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55891 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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