CVE-2025-55162Public exploitNetwork attack vector

Session hijacking via invalid cookie deletion

Published Sep 3, 2025 · Updated Sep 4, 2025

Insufficient session expiration in affected Envoy OAuth2 filter releases allows attackers to retain account access through a shared browser. The signout path builds expired Set-Cookie headers for configured __Secure- or __Host- names without the required Secure attribute, so browsers reject the deletion. Exploitation requires a prior user to log in and attempt logout on the same browser; the next user can access the retained session and its account data.

CVSS severity6.3
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient session expiration in affected Envoy OAuth2 filter releases allows attackers to retain account access through a shared browser. The signout path builds expired Set-Cookie headers for configured __Secure- or __Host- names without the required Secure attribute, so browsers reject the deletion. Exploitation requires a prior user to log in and attempt logout on the same browser; the next user can access the retained session and its account data.

The record

CVE
CVE-2025-55162
Published
Sep 3, 2025
Updated
Sep 4, 2025
Vendor
Envoy Proxy
Product
Envoy
Classifications
CWE-613, T1539
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=<= 1.32.0, < 1.32.10
  2. Affected versionversion=>= 1.33.0, < 1.33.7
  3. Affected versionversion=>= 1.34.0, < 1.34.5
  4. Affected versionversion=>= 1.35.0, < 1.35.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Envoy Proxy · Envoyversion=<= 1.32.0, < 1.32.10; version=>= 1.33.0, < 1.33.7; version=>= 1.34.0, < 1.34.5; version=>= 1.35.0, < 1.35.1

Published CVSS scores

6.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:L/A:N
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-613Insufficient Session Expiration
T1539Steal Web Session Cookie

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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