CVE-2026-32935Network attack vector

Plaintext disclosure via variable-time CBC unpadding

Published Mar 20, 2026 · Updated Mar 20, 2026

Timing side channel in phpseclib 0.1.1 through 1.0.26, 2.0.0 through 2.0.51, and 3.0.0 through 3.0.49 allows remote attackers to read plaintext. The AES-CBC _unpad method short-circuits a logical OR when validating the last-byte padding length, causing invalid lengths to return in observably different time. An unauthenticated remote attacker who can submit chosen ciphertexts and measure repeated responses can use the timing oracle to recover encrypted plaintext; integrity and availability are unaffected.

CVSS severity8.2
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Timing side channel in phpseclib 0.1.1 through 1.0.26, 2.0.0 through 2.0.51, and 3.0.0 through 3.0.49 allows remote attackers to read plaintext. The AES-CBC _unpad method short-circuits a logical OR when validating the last-byte padding length, causing invalid lengths to return in observably different time. An unauthenticated remote attacker who can submit chosen ciphertexts and measure repeated responses can use the timing oracle to recover encrypted plaintext; integrity and availability are unaffected.

The record

CVE
CVE-2026-32935
Published
Mar 20, 2026
Updated
Mar 20, 2026
Vendor
phpseclib
Product
phpseclib
Classifications
CWE-208
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 20, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 1.0.27
  2. Affected versionversion=>= 2.0.0, < 2.0.52
  3. Affected versionversion=>= 3.0.0, < 3.0.50

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

phpseclib · phpseclibversion=< 1.0.27; version=>= 2.0.0, < 2.0.52; version=>= 3.0.0, < 3.0.50

Published CVSS scores

5.9NIST NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
8.2GitHub, Inc.CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-208Observable Timing Discrepancy

Public exploit references

No public exploit references are available in this record.

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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